Vol. IV No.1

For Private Circulation

TECHNICAL MAGAZINE

The Ramco Cements Ltd“Auras Corporate Centre” I Floor,

98A, Dr. Radhakrishnan Road, Mylapore, Chennai - 600 004

Phone : 044-28478666, 28477582 Email : akp@ramcocements.co.in

Editorial Committee

Advisory Board Mr. A.V. Dharmakrishnan

Mr. Balaji K. Moorthy

Honorary ChairpersonDr. Bhanumathi Das

EditorEr Anil Kumar Pillai

MembersEr Muthukumar

Er SureshEr Indrajit Mandal Er Kevin K.Charly

Er Shashank SharmaEr Suraj

Er Chandi Prasad MohantyEr Venkatesh Pulavarty

Er FarishEr Ravi G

Er SreenidhEr R.RamachandranEr Karthick Ganesh

Er JagadeesanEr Pon Prabhu

For Private Circulation

Vol. IV No.1

Contents

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Message 3 Shri Ramasubrahmaneya Rajha 4 From the desk of INSWAREB 6 Chairman & Managing Director Shri P.R.Venketrama Raja 7 Awards & Appreciations 8 Strength behavior of Fibre Reinforced Polymer Strengthened Beam 10 Self Curing Plasters from Ramco Dry Mix 15 Collaboration with Engineering CollegesAwareness on Cement & Concrete Technology 16 Projects using Ramco Cement 17 Interaction with Construction Professionals 18 MACE Division : Interaction at Construction sites and Offices 19

Effect of ground flyash on the mechanical properties Of cement mortar 20 Feedback from Construction Professionals 25 Indian Standard Codes on Cement – Major Revisions and Additions 26 FAQ’s 27

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A.V.DHARMAKRISHNANChief Executive Officer

BALAJI K .MOORTHY Executive President – Marketing

Message

Dear friends ,

It is a matter of great sorrow that our most respected and beloved Chairman and Managing Director Shri P.R.Ramasubrahmaneya Rajha, who led us and guided us over the last five decades is no more with us. Our Chairman was not only loved and respected by RAMCO family members but also by millions in India and abroad. He was well known as a top industrialist, a thought and technology leader, an educationist par excellence, a philanthropist with a large heart and ever ready to give a helping hand to the needy and poor, deeply spiritual, an avid reader, a lover and promoter of arts and culture and above all a very gentle and kind human being who firmly believed in strong family bonds. He was known for his humility and modesty and his very simple lifestyle. He was easily approachable and anyone wanting to see him could easily get an appointment and meet him.

Our Chairman had untiringly practiced the teachings and thoughts of our Founder and consistently taught us to follow the same. Our Founder had advised our Chairman to always protect the interests of the stakeholders - be it the shareholder or dealer/customer or supplier or transporter/service provider. Our Chairman implemented and instilled the wonderful value systems that our Founder believed in - hard work, honesty, Integrity, transparency, simplicity, commitment etc. Our Chairman had stressed to all of us that in a highly competitive, price sensitive industry, giving excellent customer service is extremely important.

Our Chairman's passing on is indeed a great loss to all of us. We are all very fortunate that the Vice Chairman of RAMCO Group of Companies Shri.P.R.Venketrama Raja, has, since then, been appointed as Chairman of Ramco Group of Companies and will continue to lead us and guide us in all our activities in the future.

Our former Chairman always used to say that we are not merely in the business of manufacturing cement; but we are involved in the building of a strong India. Let's together work hard in building a beautiful and strong India which our future generations will be proud of.

Wish you and the members of your family the very best. And thank you for standing by us in our hour of anguish and distress.

Noted industrialist and philanthropist, Shri P. R. Ramasubrahmaneya Rajha passes away

Shri P.R.Ramasubrahmaneya Rajha, Chairman of the Rs.6,000 crore Ramco Group of Companies, a well-known industrialist and philanthropist, passed away in Rajapalayam, Tamil Nadu, on 11th May, 2017. He was 82 years old and is survived by his wife, son and two daughters.

He was born in 1935 to Shri P.A.C. Ramasamy Raja - the Founder of the Ramco Group and a true son of the soil who revolutionized the industrial sector in Tamil Nadu. The young Ramasubrahmaneya was sent by his father as an ordinary worker to Binny Mills – a stint that inculcated in him a deep belief in hard work and a feeling of compassion for his co-workers - values which he held on to during his entire business life.

On the demise of his father Shri P.A.C. Ramasamy Raja in 1962, the mantle of guiding the fortunes of the Ramco Group fell on the young shoulders of Ramasubrahmaneya Rajha, who was then only 26 years old. In his dying moments, the father elicited a promise from Ramasubrahmaneya Rajha that he would untiringly work for the Company’s shareholders and protect their interests. As subsequent years were to show, Shri Ramasubrahmaneya Rajha not only kept the promise, but ensured manifold returns to the shareholders, even during times when other companies hardly made any profits.

He achieved this through an intrinsic faith in adapting to new technologies and management methods in every sector that the Group invested in. He complemented this with innovative and efficient management practices, with the result that Ramco Group companies have consistently out-performed the industry in every sector. His visionary zeal was behind the setting up of modern manufacturing plants, spinning mills and educational and charitable institutions all over India.

Before foraying into other parts of the country and beyond, he single-handedly transformed the landscape and fortunes of Rajapalayam and its surrounding districts, dotting the area with several industrial units.

The legacy that Shri Ramasubrahmaneya Rajha leaves behind is not just the very tangible financial achievements of the Group, spanning Cement, Textiles, Building Materials, Software, Thermal Power and Wind Farms - his true legacy is the robust value system, commitment to ethics and the manifold community development programmes that he spearheaded, which is the bedrock of the huge equity and goodwill that the Group enjoys today.

In his own words, “There should be a determined effort to bring a certain culture across the organisation. It should be nurtured carefully and everyone should believe in it. The people at the top should be role models by practising that culture in their day-to-day approach and thoughts. Each organisation must have its unique culture and that is the only strong binding force. The culture in our organisation is that in whatever we do, we must basically follow ethical values and try to achieve our goals.”

Shri Ramasubrahmaneya Rajha was intensely religious, simple in his habits and a dedicated father and husband. As he himself put it, “One should be loyal to himself. The question is, am I loyal to my profession and to my way of living. The question of loyalty to any individual does not arise. One should be loyal to one’s convictions and professionalism. When this is practised, balance is achieved.”

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Shri Ramasubrahmaneya Rajha

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FROM THE HINDU DATED MAY 12th, 2017

Leading industrialist P.R. Ramasubrahmaneya Rajha, Chairman, Ramco Group, passed away in Rajapalayam on Thursday.

He was 81. He is survived by his wife R. Sudarsanam, two daughters and son P. R. Venketrama Raja.

Mr. Rajha, born in 1936 as the only son of P.A.C. Ramasamy Raja, founder of Ramco Group, played a big role in building the Group into a $1 billion industrial conglomerate with interests spanning cotton and synthetic yarn, cement, building products, software solutions, wind-energy and bio-technology, among others.

The media-shy Rajha was a philanthropist, educationist and an ardent devotee of the Sringeri Mutt.

In the mid-1950s, he wanted to pursue higher education in textile technology in Manchester. But his father thought otherwise.

He made him undergo an 18-month apprenticeship in Buckingham and Carnatic Mills in Chennai for a monthly salary of75.

Later, he was sent to the Madura Mills in Madurai as graduate commercial apprentice.

But he had to take up his father’s role at the age of 26 when Ramasamy Raja died in 1962.

In tune with the timesMr. Rajha was always proud of his father and believed

in his philosophy that “a contended worker will give to the employer better work and therefore better profits.”

The Rajapalayam Mills has not seen any labour unrest since it was inaugurated on September 5, 1938.

Mr. Rajha always adapted to changing times and he used to attribute his success to an endeavour to make customers addicted to his products through sheer quality.

A Good SamaritanHe always played the role of Good Samaritan not only

for his employees but also to all around him. In times of adversity, he lent a helping hand.

Reacting to his demise, Tamil Nadu Chief Minister Edappadi K. Palaniswami expressed his condolences and said the passing away of Mr. Rajah was an irreparable loss to the industry.

It was Mr. Rajha who established various industries in Virudhunagar, he added.

BUSINESS LINE DATED MAY 11th , 2017 PR Ramasubrahmaneya Rajha, 82, Chairman of the

Ramco Group, passed away at Rajapalayam today. He had been ailing for some time.

He is survived by a son, PR Venketrama Raja, and two daughters R Nalina Ramalakshmi and S Sharada Deepa.

Ramasubramaneya Rajha took over the reins of the Ramco Group in 1962 after the demise of his father PAC Ramasamy Raja and grew the businesses into a $1-billion conglomerate. The group has a diversified presence in cement, spinning mills, IT and education.

Expressing deep regrets over the demise of Rajha, N Srinivasan, Vice-Chairman and Managing Director, India Cements, who has known him for over four decades, said: “I am shocked to hear the news of the passing away of Shri Ramasubrahmaneya Rajha. He was one of the pioneers of the cement industry and his contribution has been immense. It is hard to express my feelings when I have known him for over 40 years. I convey my condolences to his son and all family members.”

As much as an industrialist, Rajha was known for his spiritual outlook, philanthropy and as a patron of arts. A graduate in physics from the Loyola College, he started his career in the textile business in mills in Madras, as Chennai was known then, and in Madurai. He was 26 when he took over the management of Rajapalayam Mills, promoted by his father, in 1962.

The flagship cement business under Ramco Cements multiplied from a 200 tonne a day unit to a 16.5-million-tonne a year giant with five integrated cement plants and four grinding units.

THE INDIAN EXPRESS DATED MAY 11th , 2017 Noted industrialist and chairman of diversified business

conglomerate Ramco Group of companies, P R Ramasubrahaneya Rajha passed away in Rajapalayam today, following a brief illness, family sources said.

He was 82 and is survived by wife and son P R Venkatarama Rajha, the Vice-Chairman and Managing Director of the Group.

Ramasubrahmaneya Rajha, is the son of Ramco Group Founder, P A C Ramasamy Rajah.

Ramco group, which began its journey as a spinning mill in 1938, has its presence in various verticals including Ramco Systems (IT sector), Ramco Cements, (cement), Ramco Industries, Rajapalayam Mills Ltd, Thanjavur Spinning Mills Ltd.

Meanwhile, Tamil Nadu Chief Minister K Palaniswami condoled the death of Ramasubrahnaneya Rajha saying his death has left a void in the industrial world.

Palaniswami extended his deepest condolences to the family of the deceased, an official release said.

"Yada yadahi Dhrmasya Glanir bhavathi Bharatha

Abhyutthanamadarmasya tadatmaanam sirjamyaham

Parithranaya sadhunam vinasaya cha dushkrutam

Dharma samsthapanarthaya sambhavami yuge yuge"

When untoward events happen in the society in any context then the great Almighty personifies himself through sagunakara to establish the righteous path. PPC concept was killed in Indian cement scenario during 70-90s for adopting unscientific process techniques due to lack of comprehensive knowledge on fly ash. CPWD had banned PPC in all its construction. Late Shri Ramasubrahmaneya Rajha transformed such pessimistic environment into optimistic environment with his vision.

As free lance scientists, we never accepted anybody as our boss or patron. But both of us sincerely accepted Late Ramasubrahmaneya Rajha as our patron for his vision in tapping our scientific potential. The country owes a lot to him for his pioneering efforts in promoting blended cements duly endorsing logical marketing strategies.

It was winter months in Visakhapatnam in 1998. Economic Times had published an elaborative article, authored in interaction with us, on blended cements, concretes and durability issues. We were told that Late Shri Ramasubrahmaneya Rajha had seen that article in ET, impressed with its inputs and was keen to interact with us for translating the western practices into positive market development in Indian cement scenario. We were surprised to learn that an individual of Mr. Rajha’s stature had the time to read a technical article and decided to launch an action plan in revolutionising the Indian cement industry.

Since we were already working on cement and concrete, publishing various articles in seminars and newspapers, we readily agreed to work on it to turn it into reality. While many Cement Companies were hesitating to venture into blended cement in 1999-2000, it was Madras Cements Ltd. as they were known then, who took the initiative to draw the attention of construction industry to analyse the facts behind the success of blended cement. Madras Cements Limited decided to swim against the tide in the cement industry which was then predominantly popularizing only OPC cement and did yeoman service in boldly highlighting the advantages and benefits of blended cements. This brought about a paradigm shift in the Indian cement industry which in turn lead to the adoption of PPC as prime product by many cement plants during 2000-03.

Mr Rajah has immense respect for scientific fraternity and in turn fondly revered by the fraternity too at international plateau. While we approached him, appraising the scope of conferring international experts on blended cements world over by conducting international seminars in association with CANMET/ACI, he had not only cleared the financial support but extended his consent to be its Chairperson and carried forward the mission by addressing personal letters to all doyens of cement industry about the purpose of such international event.

He was not only a corporate head responsible for running the businesses profitably, but also a technically savy person craving for quality upgradation constantly. This inner soul in him tapped the research potential in us and that, in turn, resulted in the establishment of Ramco Research & Development Centre (RRDC), having unparallelled research facilities, boldly appointing a lady, Dr Bhanumathidas as its Head.

Late Rajah was keen that RRDC should keep pace with the global research in cement, concrete technology and other building materials in order to uphold the commitment of the Nation for Sustainable Development. Lot of data on durability of blended concretes developed in RRDC has become handy and we are proud to get involved in the activities of RRDC right from the concept under the guidance of Shri Rajha. It is quite amazing that his wisdom and vision on different technical and technological issues are indeed splendid.

Notwithstanding good corporate governance, Shri Rajha has been blessed with many other facets of accomplished life. He is well known for his commitment towards education where he has established schools and colleges to cater to the academic needs of students in surrounding villages. He has also established Veda Pathasala to uphold Hindu sanathana dharma. He is a popular philanthropist and also had been vibrant respondent to divine activities patronising activities in various temples.

What more is required for an accomplished soul on earth on its journey to divinity!!!

The best way of paying tributes to such towering personalities is to continue their ideologies in letter and spirit.

Dr N Bhanumathidas and N Kalidas

Concrete Technologists and founder directors of INSWAREB, Visakhapatnam.

From The Desk Of INSWAREB

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Chairman & Managing Director Shri P.R.Venketrama Raja, Ramco Group of Companies

The Board of Directors of The Ramco Cements Limited has appointed Shri P.R.Venketrama Raja as its Chairman . He is also the Chairman of the Ramco Group of Companies.

Shri P.R.Venketrama Raja is 58 years old. He did his Chemical Engineering from AC College of Technology , Madras and his MBA from University of Michigan , USA – one of the top business schools in the world.

Shri P.R.Venketrama Raja is associated with The Ramco Cements Limited as its Director from 23rd May 1985. He has been associated with the expansions and technological developments of all the projects at The Ramco Cements Limited since 1985.

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Awards and Appreciations

Late Shri Ramasubrahmaneya Rajah receiving “ILLUSTRIOUS ALUMNI AWARD” from Loyola College

Founder , Mentor & Innovator in Chief Shri P.R.Venketrama Raja receiving the “Global Influencer of the Year” award at the CII CONNECT AWARDS 2016, held in Chennai.

Green products and Services council of CII issued Green Pro certificate for Ramco Supergrade. With this RSG is certified as green product. The photo shows Mr. Murthy Rao, AVP – Process receiving certificate at the international Green building congress in Mumbai on 6th October.

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CIO 100Every year International Data

Group(IDG India), the World’s leading Technology Media, Event and Research Group, who publishes CIO Magazine in India is selecting the best 100 projects and awarding as CIO 100 award .

The CIO 100 Award is given to the organizations that use information technology in innovative way to deliver business value by creating competitive advantage, optimizing business processes, enabling growth or improving relationship with customers.

This year also we have been awarded with the prestigious CIO 100 Award held at Pune on 2nd Sep 2016 for our Logistics Optimization by integrating ERP, APO and GPS.

Appreciation award for Ramco’ s grinding unit near Chennai , Tamil Nadu

5 Stars Rated Mine

Rewards on Sustainable Development- Star Rating of MinesTRCL Ariyalur –Pudupalayam (North) – The First “5 star rated mine” in Tamil Nadu.

Our Ariyalur unit – Pudupalayam Mines North has been awarded the prestigious “FIVE STAR RATING” at the National Conclave of Mines & Minerals held at Raipur, Chhattisgarh.From Tamil Nadu, ours is the only mine that has received this award of Excellence.

Alathiyur, Ariyalur and RR Nagar units received National award for Excellence in Energy Management 2016 conducted by CII Hyderabad

CII National Award for Excellence in Energy ManagementConfederation of Indian Industry (CII) has conducted nation wide competition for Excellence in Energy Management.

The objective of the awards is to recognize and award “Excellence” in Energy Management and to establish futurity by pinpointing Carbon Emission Reduction (CDM / VER Project) initiatives focused on energy conservation.

Teams from Ramco participated in the Competition. Based on the Presentation, the panel of judges shortlisted and presented National Award for Excellence.

Strength Behaviour Of Fibre Reinforced Polymer Strengthened Beam

N. Pannirselvam1, V. Nagaradjane2 and K. Chandramouli3

1VIT University, Vellore, India

2Department of Structural Engineering, Annamalai University, Annamalainagar, India

3Priyadrashini Institute of Technology for Women, Tenali, Guntur, Andhra Pradesh, IndiaE-Mail: npannirselvam@vit.ac.in

AbstractStrengthening of structures using Fibre Reinforced Polymer (FRP) shows better promise for extending the life span of structures.

The advantages of using FRP include light weight, ease of installation, minimal labour costs and site constraints, high strength-to-weight and durability. The objective of this work is to evaluate the structural behaviour of reinforced concrete beams with externally bonded FRP reinforcement. Beams bonded with four different types of Glass Fibre Reinforced Polymer (GFRP) having 3.50 mm thickness were used. Totally five rectangular beams of 3 m length were cast. One beam was used as reference beam and the remaining beams were provided with GFRP laminates on their soffit. The variable considered for the study is type of GFRP laminate. The study parameters of this investigation included first crack load, yield load, ultimate load, first crack deflection, yield deflection, ultimate deflection, crack width, deflection ductility, energy ductility, deflection ductility ratios and energy ductility ratios of the test beams. The performance of FRP plated beams was compared with that of unplated beam. The test results showed that the beams strengthened with GFRP laminates exhibited better performance.

Keywords: beams, deflection ductility, energy ductility, fibre reinforced polymer, reinforced concrete, strength.

IntroductionFRP composite materials have been successfully used in the construction of new structures and in rehabilitation of existing

structures. FRP composite materials hold great promise for the future of construction industry. Strengthening of reinforced concrete and pre-stressed concrete structural elements may be required as a result of increase in service loads, change in usage pattern, structural degradation of concrete or defects in design or construction. Repair with externally bonded FRP reinforcement is a highly practical strengthening system, because of ease and speed of installation, efficiency of structural repair and corrosion resistance of the materials. The application of FRP poses minimal modification to the geometry, aesthetics and utility of the structure. Several studies on the behavior of reinforced concrete beams strengthened with FRP composite sheets provided valuable information regarding the strength, deformation, ductility and long-term performance of the FRP strengthening systems. Installation of externally bonded up-gradation systems using FRP is faster and less labour-intensive.

FRP plating is a versatile technique which can be applied equally well for existing RC beams and new ones. Plating of FRP laminates results in increase of composite moment of inertia of the section, thus making it behave with more stiffness after plating. The present study is aimed at investigating the effect of FRP plate on the performance of FRP plated RC beams.

FRP is a composite material generally consisting of carbon, aramid or glass fibres in a polymeric resin matrix. FRP composites are, as the name suggests, a composition of two or more materials which, when properly combined, form a different material with properties not available from the ingredients alone. Depending on the ingredients chosen and the method of combining them, properties of FRP can be controlled. Reinforced Concrete (RC) is a good example of a composite. The steel rebars provide excellent tensile strength and the concrete provides compressive strength and transfers the load between the steel bars.

The major constituents of FRP are the fibre and the resin. The mechanical properties of FRP are controlled by the type of fibre and durability characteristics are affected by the type of resin. The commonly used types of FRP are: i) Carbon Fibre Reinforced Polymer (CFRP), ii) Glass Fibre Reinforced Polymer (GFRP), iii) Aramid Fibre Reinforced Polymer (AFRP).

Different systems of externally bonded FRP reinforcement exist. The two commonly used systems include wet lay-up system and prefab system. In the former system, dry unidirectional fibre sheet, dry multidirectional fabric, resin pre-impregnated uncured unidirectional fabric sheet, resin pre-impregnated uncured multi-directional fabric/sheet, dry fibre tows or pre-impregnated fibre tows are utilized. The fabric can be either directly applied into the resin that has been applied on the concrete surface or can be impregnated with resin and then applied wet on the concrete surface. In the latter system, pre-manufactured cured laminates, shells, jackets or angles are installed through the use of adhesives.

FRP can be applied for strengthening a variety of structural members like beams, columns, slabs and masonry walls. Beams and slabs may be strengthened in flexure by bonding FRP strips at the soffit portion along the axis of bending. Shear strengthening of beams may be achieved by bonding vertical or inclined strips of FRP at the side faces of beams. Strengthening of beams in both flexure and shear may be achieved by wrapping around the cross section of beams in U-Shape.

Literature ReviewTeng et al. (2002) presented a finite element study for interfacial stresses in reinforced concrete beams strengthened with

a bonded soffit plate. They validated the finite element results with the predictions of the approximate analytical solution by

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Smith and Teng. The authors varied parameters such as thickness of adhesive layer, the elasticity modulus of adhesive layer, the thickness of soffit plate. They concluded that the interfacial stresses were found to increase with a reduction in adhesive thickness and an increase in adhesive elastic modulus, plate thickness/elasticity modulus. They have used fine mesh for analyzing the point of stress singularity in a plated RC beam.

Chen and Teng (2003) developed a simple, accurate and rational design model for the shear capacity of FRP strengthened beams which fail mainly by FRP debonding. The authors validated their model against experimental data collected from the existing literature. Their model explicitly recognizes the non-uniform stress distribution in the FRP along a shear crack as determined by the bond strength between FRP strips and concrete. The design proposal developed by them can be directly used for practical design.

Francois Buyle-Bodin (2004) examined the performance of rectangular simply supported reinforced concrete beams with externally bonded reinforcement made of carbon fibre reinforced polymer plates. The author studied the load-carrying capacity of CFRPEBR beams by delaying end peel failure. The author prevented the brittle failure by use of clamps at the ends of the beam, bonding of lateral perpendicular or inclined strips and U-wrapping of shear spans with carbon fibre textile. The author concluded that the lateral bonding of CFRP strips and U-wrapping using carbon fibre textile controls the debonding cracks and delay the premature end failure of the beams. The load carrying capacity is enhanced, and the ductility is increased.

Lin et al. (2005) presented an experimental study on strengthening reinforced concrete beams using pre-stressed glass fibre reinforced polymer (PGFRP). The ultimate loads and the deflections of strengthened RC beams using GFRP and PGFRP sheets were tested and compared. They reported that the beams strengthened with PGFRP sheets can withstand larger ultimate loads than beams with ordinary GFRP sheets. The deflections of the beams with PGFRP sheets are smaller than those of beams with GFRP sheets under the same external loads. The ductility of the over-strengthened beams was especially smaller.

Ginseppe Campione (2006) has studied on the influence of FRP wrapping techniques on the compressive behaviour of concrete prisms. The specimens were prism with square cross section externally wrapped with carbon fibre reinforced plastic sheets. The parameters analyzed were local reinforcements at the corners and continuous layers, horizontal and vertical continuous strips, number of continuous layers, and length of the specimens. The author concluded that the test results showed a good agreement with an analytical model prepared to determine the maximum bearing capacity of compressed concrete members with square cross section and externally wrapped with FRP with different configuration.

Xiong et al. (2007) have tried to device a way for preventing tension delamination of concrete cover at midspan of FRP strengthened beams by combining CFRP and GFRP sheets at midspan of a beam. They have used unidirectional carbon fibre reinforced polymer sheets on the tension face of the beams and bi-directional GFRP sheet wrapped on 3 sides of the beam continuously. The feasibility and potential advantages of the attempt are discussed. They have concluded that the hybrid CFRP-GFRP system could not only prevent the tension delamination of the bottom concrete cover, but also lead to a significant increase of deformation capacity of the strengthened beams at a very low cost compared to CFRP strengthening.

Objectives Of The StudyThe objectives of the current research work include:

a. To study the impact of externally bonded Chopped Strand Mat (CSM), Woven Roving (WR), CSMWRGFRP and Uni-directional (UD) GFRP laminates on strength, deformation and ductility of the test beams;

b. To examine the composite action of the GFRP laminates at all load levels; and

c. To understand the associated cracking and failure mechanisms.

Research SignificanceFRP strengthening provides an ideal system for achieving the strength and ductility requirements of new constructions as

well as existing structures. Beams occupy a vital role in the load transfer mechanism of all structures. Beams form the first line of defense against almost all types of failures found in structural systems. In a developing country like India, the cost of FRP system is also a major concern. Since the cost of GFRP is the lowest and since it is the most commonly available material GFRP was considered suitable for the study. Hence, this research study investigated the characteristics of RC rectangular beams strengthened with externally mounted GFRP laminates.

Materials And Methods

MaterialsCement concrete having characteristic

compressive strength of 33.50 MPa was used for casting the beams. The longitudinal steel reinforcement was provided using Fe 415 grade steel rods and shear stirrups were provided using Fe 250 grade steel rods of 8 mm diameter. The tensile steel reinforcements were provided at 0.40% of the gross cross sectional area of the beam.

The properties of FRP used for the experimental work were tested in an independent laboratory and listed in Table-1.

Table-1. Properties of GFRP laminates.

Property CSM Woven rovings Uni-directional

Glass content % 25-40 45-60 60-90

Specific gravity kg/cm3 1.4-1.5 1.5-1.8 1.7-2.2

Tensile strength MN/m2 63-140 230-340 530-1730

Tensile modulus GN/m2 6-12 13-17 28-62

Compressive strength MN/m2 130-170 100-140 310-480

Flexural strength MN/m2 140-250 200-270 600-1800

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Table-2. Specimen specifications.

S. No. Beam designation %Steel reinforcement Type of GFRP Thickness of GFRP

1. SR 0.40 - -

2. SRCSM 0.40 CSM 3.50

3. SRWR 0.40 WR 3.50

4. SRUD 0.40 UD 3.50

5. SRCSMWR 0.40 CSM+WR 3.50

Table-3. Loads, deflections and crack width at salient stages.

S. No. Specimendesignation

Firstcrack load

(kN)

Yield load (kN)

Ultimate load (kN)

Deflection at first

crack (mm)

Yield deflection

(mm)

Ultimate deflection

(mm)

Crack width at

yield (mm)

Maximum Crack width

(mm)

1. SR 17.17 17.17 34.34 4.52 11.17 30.20 0.12 1.20

2. SRCSM 17.17 22.07 36.79 3.38 8.04 32.73 0.14 1.00

3. SRWR 24.53 39.24 49.05 6.55 8.44 35.60 0.18 0.60

4. SRUD 29.43 44.15 58.86 7.77 11.58 32.83 0.36 0.82

5. SRCSMWR 34.34 51.50 63.77 7.39 7.98 35.49 0.24 0.62

SpecimensA total of five reinforced concrete beams were cast. One without plating and four with CSMGFRP, WRGFRP, Uni-directional

GFRP and combination of CSMWRGFRP plating of 3.5 mm thickness. The details of the specimen are presented in Table-2.

The soffit portions of beams were cleaned and GFRP plates were bonded using adhesive. Figure-1 shows the application of GFRP plate to beam soffit. The beams were cured for seven days to permit the adhesive to gain strength before testing.

Testing of beamsThe beams were tested under four point bending by applying

two equal loads dividing the span into three equal parts. Deflectometers were fixed at the mid span and below the loading points to measure the deflection. Two deflectometers were fixed on top of the beam near a support at a spacing of 100 mm in order to measure the curvature. The load was applied through a hydraulic jack placed on top of a spreader beam. The test setup is shown in Figure-2.

The strains near top and bottom of the beam were measured using DEMEC gauge with four measuring pins located at 200 mm c/c distance. The loading was applied monotonically at increments of 2500 N and all deflection readings were measured for each load increment. The extension at rebar level and compression at top of the beam were measured using the DEMEC gauge. The readings on the two dial gauges placed on top surface of the beam over support section were also taken.

The failure of reference beams without any GFRP plating was preceded by high levels of deformation after yield point. But, the failure of GFRP plated beams was observed to be due to one of the following reasons: delamination, ripping of cover concrete along with GFRP plate or fracture of laminate.

Results And DiscussionsThe load-deflection curves for five beams are shown in

Figure-3. In all the cases, the beams with GFRP plating reached higher load levels. The stiffness of the GFRP plated beams was higher than that of the unplated beams, resulting in higher load carrying capacity at lower deformation levels.

The summary of salient load-deflection results is presented in Table-3. For WRGFRP plated beams, the first crack loads showed increase of 71.43% over the corresponding reference specimens.

Note: CSM- Chopped Strand Mat; WR- Woven Rovings; UD- Uni-Directional FRP Plating

Figure-1. Bonding GFRP plate using adhesive.

Figure-2. Test setup.

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Table-4. Deflection and energy ductility values.

S. No. Specimendesignation

Deflection ductility

Energy ductility

Deflection ductility ratio

Energy ductility ratio

1. SR 2.70 3.81 1.00 1.00

2. SRCSM 4.07 6.63 1.51 1.74

3. SRWR 4.22 8.28 1.56 2.17

4. SRUD 2.84 4.93 1.05 1.29

5. SRCSMWR 4.45 8.34 1.64 2.11

Figure-3. Load deflection behaviour.

The increase in yield load was higher for WRGFRP plated beams when compared to the CSMGFRP plated beams. Plating with CSMGFRP laminates resulted in less deflection compared to plating with WRGFRP.

This might not be taken as an indication of increase in stiffness value of CSMGFRP plated beams, since the yield load attained by these beams are much lower than those attained by WRGFRP plated beams. The application of WR fibre reinforced laminate resulted in higher ultimate strength values compared to CSM reinforced laminates.

Figure-4. Deflection ductility.

Table-4 shows the deflection and energy ductility values. In the case of GFRP plated beams, the deflection ductility values showed a reduction or very meagre increase. The beams SRCSM, SRWR, SRUD and SRCSMWR showed increase in deflection ductility by 50.57%, 56.29%, 5.18% and 64.48%, respectively, over the control beam. Energy ductility was higher for beams with thicker GFRP plating. The beams SRCSM, SRWR, SRUD and SRCSMWR with steel ratio of 0.40% exhibited 74.01%, 117.32%, 29.40% and 118.90% increase in energy ductility over the beam SR.

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The results indicate that energy ductility is clearly influenced by the thickness of GFRP plating, exhibiting higher levels of increase for higher thickness of plating. The application of GFRP plating contributes to the increase in strength as well as deflection capacities in combination. Yield ductility, which depends only on deflection values, does not show as much improvement as the energy ductility in response to applied thickness of GFRP plating. Deflection ductility and Energy ductility values are presented in Figures 4 and 5.

ConclusionsThe performance of GFRP plated RC beams increased with regard to strength and deformation capacity. The following salient

conclusions were drawn from the present investigations:

i) The ultimate load for GFRP plated RC beams increased by a maximum of 42.84% for SRWRGFRP plated beam, by 71.40% for SRUDGFRP plated beam and by 85.70% for SRCSMWRGFRP plated beam, when compared to the reference beam.

ii) The type of GFRP influenced the performance of the GFRP plated beams. SRUDGFRP resulted in better performance when compared to SRCSMGFRP.

iii) Deflection ductility values for beams showed increase up to 64.48% over the corresponding reference beams.

iv) Energy ductility values increased by up to 118.90% for 3.5 mm thick GFRP plated beams.

ReferencesACI Committee. 2001. Design and Construction of Concrete Reinforced with FRP Bars. American Concrete Institute, Farmington

Hills. Michigan. USA.

Chen J.F. and Teng J.G. 2003. Shear Capacity of FRP Strengthened RC Beams: FRP Debonding. Construction and Building Materials. 17: 27-41.

Francois Buyle-Bodin. 2004. Use of Carbon Fibre Textile to Control Premature Failure of Reinforced Concrete Beams Strengthened with Bonded CFRP Plates. Journal of Industrial Textiles. 33(3): 145-157.

HUANG Yue-lin, HUNG Chien-hsing, YEN Tsong, WU Jong-hwei and LIN Yiching. 2005. Strengthening Reinforced Concrete Beams using Prestressed Glass Fiber-Reinforced Polymer-Part I: Experimental Study. Journal of Zhejiang University Science. 6A(3): 166-174.

HUANG Yue-lin, HUNG Chien-hsing, YEN Tsong, WU Jong-hwei and LIN Yiching. 2005. Strengthening Reinforced Concrete Beams using Prestressed Glass Fiber-Reinforced Polymer-Part II: Analytical Study. Journal of Zhejiang University Science. 6A(8): 844-852.

Ginseppe Campione. 2006. Influence of FRP Wrapping Techniques on the Compressive Behaviour of Concrete Prisms. Journal of Cement and Concrete Composites. 28(5): 497-505.

Teng J.G., Zhang J.W. and Smith S.T. 2002. Interfacial Stresses in Reinforced Concrete Beams Bonded with a Soffit Plate: A Finite Element Study. Construction and Building Materials. 16: 1-14.

Xiong G.J., Jiang X., Liu J.W. and Chen L. February 2007. A Way for Preventing Tension Delamination of Concrete Cover in Midspan of FRP Strengthened Beams. Journal of Construction and Building Materials. 21(2): 402-408.

Figure-5. Energy ductility.

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Dry Mix division has the following range of products

• Ramco Ready Mix Plasters

• Ramco Tile Adhesives

• Ramco Block Fix

• Ramco Super Fine Putty

• Ramco Plastering Compound

The Dry Mix division has been offering the customer more innovative products customised to meet specific requirements .Ready Mix plasters is a scientific proportion of cement + river sand / m sand + special Additives .The distinct advantages a ready mix plasters offers over the conventional system of cement / sand Plasters are that they offer very accurate proportions of raw materials and offer drastic reduction in plastering cracks /better workability on account of addition of special additives .

The 5 variants of ready mix plasters are

GPP ( General Purpose Plaster ) is a 1: 4 CEMENT /SAND RATIO product which was the original recipe adopted from m tec Germany with whom RAMCO has technical collaboration

GPP1 which is a 1: 5 CEMENT /SAND RATIO product developed in –house at the Dry Mix Plant as most construction sites in India were using this mix ratio . 100% cleaned , dried and graded river sand is mixed in GPP1

GPP2 is a 1: 5 CEMENT /SAND RATIO product.The sand component is a accurate proportioning of 50% river sand and 50% manufactured sand which is cleaned/ dried and graded. This product was also developed in –house at the Dry Mix Plant.The need for this product arose from the fact that many construction sites in the absence of good quality river sand were migrating towards manufactured sand mixed with cement for Plastering . This would be useful in places where the quality of manufactured sand is not at par.

WRP ( WATER REPELLENT Plasters ) is a specific product developed for external Plastering applications with a water repelling compound factory mixed to beat the conventional system of mixing water repellent compounds at the construction sites where error in dosaging is very likely

In addition to the above another product that is offered is

Polymer Modified Plasters which is a plaster fortified with polymers ( in addition to cement and 100% river sand ) and was specifically developed at the Dry Mix Plant for the RBI project in Chennai where over 2000 tonnes was supplied.

Based on the customer requirement at site there was a need for SELF CURING PLASTER to overcome the existing practise of manual curing at construction sites. This manual curing cannot be a 100% controlled mechanism as there was a huge manual component prone to error. Any Plaster which is not adequately cured could develop Plastering cracks. To overcome this deficiency SELF CURING PLASTERS at Ramco’s Dry Mix Plant is developed.

In the SELF CURING PLASTERS a self curing agent is used which minimises the water evaporation from the mortar and thus increases its water retention capacity, thereby ensuring the proper hydration to achieve the required strength. By bringing in the water retentive chemical additive the need for the conventional curing process, the labour and supervision, thereof, is eliminated.

Number of extensive trials have been done with Ramco Self Curing Plaster at sites at Bangalore and the results have been encouraging. This concept of self curing plaster would be well accepted among the architects/builders community.

RAMCO DRY MIX RANGE OF PRODUCTSRamco Dry Mix offers the most comprehensive world class

products from ceiling to walls to floors . These products are Manufactured from the state-of-the art plant located at Sriperumbudur, Chennai. The Dry Mix business today has evolved to give customised solutions based on Market requirements. SELF CURING PLASTERS & GPP2 which is a scientific proportion of cement + river sand + manufactured sand which is cleaned, dried and graded are two such product innovations , which is generating a lot of interest in the construction industry. Ramco Tile Fix offers a wide range of variants to suit application for various grades of Tiles in the market today. Manufactured with only RAMCO OPC , our Tile Adhesives offer the most consistent batch to batch quality. Ramco Dry Mix Division is all set to launch Ramco Tile Grouts which will be offered in 10 exciting colours and will be the first coloured product offered from TRCL . Ramco Dry Mix products are today specified in many landmark projects across South India. The fact that most of the products offered by Dry Mix Division have been developed in house at our Dry Mix Plant is a matter of great pride for all of us at TRCL.

Self Curing Plasters From Ramco Dry Mix TECH M

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Post graduate students of Anna University , Chennai during their visit to RRDC

Students of SRM Easwari Engineering College – Chennai visited Ramco’s grinding unit near Chennai for Industrial training .70 civil engineering students participated and Shri R Meenashisundaram, SGM - Works addressed the students.

Collaboration with Engineering Colleges – Awareness on

Cement & Concrete Technology

Concrete Contest at Jeppiaar Engineering College, Chennai

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Projects using Ramco cement

Circuit House at Bankura in West Bengal constructed using RAMCO Cement

Thevara Bridge Construction in Kerala constructed using Ramco cement . The grade of concrete used is M 45.

JSW Plant constructed using Ramco Cement at Salboni , West Bengal

Brigade Project at Bangalore used Precast Technology for their residential project .

RAMCO SUPERFAST, rapid hardening cement as per IS 8041 was used for the project

The precast elements could be demoulded at 18hrs (achieving 15Mpa strength) and even 15hrs in summer season. This also ensured production of precast elements on daily basis.

The precast elements were casted in an open type factory, which consisted of both tilting & non tilting type of tables. Tilting type of tables were imported from Italy whereas non-tilting type tables were fabricated by our in-house fabricators. The elements were demoulded after achieving minimum of 15Mpa strength. Water based curing compound imported from USA was used to ensure curing of precast elements. Whole super structure was built with precast elements (wall panels, slabs, beams, staircase flights including landing elements).

The total number of precast elements for the project was around 20,000 in number with a quantity of 20,000 cubic meters of concrete

Precast Construction At Brigade Orchids, Bangalore (Inputs By Er Santhosh, Mace – Bangalore)

Interaction With Construction Professionals

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SGM ( Marketing), DGM (Technical Services), DGM (Brand Management) , DGM (Marketing) with Col Nallathambi during Engineers Meet at Chennai

Engineers interacting with RAMCO team at Chennai

Guest Lecture on “ Can Concrete be customised” was given at the Institution of Engineers – Chennai Centre . Seen in the photograph ( from left to right) are Er Zacharia George , Structural Consultant ; Er Sundarasekharan , Secretary , Institution of Engineers ; Er K.P.Ramanathan , Chairman , Institution of Engineers ; Er Anil Kumar Pillai , The Ramco Cements Limited.

Engineers inside Alathiyur Plant understanding the packing operations

Engineers understanding the cement manufacturing process at the Central Control Room

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Releasing of TechMantra during the Valedictory function of TECHNOWEEK 2016 at Hotel Ocean Pearl , Mangalore Ramco team participated at CET Alumni Association of

Global Meet , Bolgatty Palace , Ernakulam

Cube test done by MACE Engineer - Sanjib Routh for Municipal Project at Bankura

Concrete Casting attended by our MACE team in West Bengal

MACE Division : Interaction at Construction sites and offices

Er Rudresh of Bangalore who is involved in execution of residential apartments . Our MACE Engineer Er Dinesh has been offering testing services to ensure good quality concrete is casted.

Mr.Shankar of VTV Construction Pvt. Ltd is involved in construction of residential projects and is a user of Ramco Cement. MACE Engineer Er.Sharan basava has conducted concrete trials at their site and also casted cubes to ensure quality concrete .

Er.Chaithanya Reddy of Aravind constructions uses RAMCO Cement for his projects . MACE Engineer Er Shivakumar has been rendering technical services to his project to ensure that quality concrete is made.

Effect of ground fly ash on the mechanical properties of cement mortar

D.K. Bera, A.K. RathFaculty School of Civil Engineering,

KIIT University, Bhubaneswar, Odisha, 751024,India dberafce@kiit.ac.in, akrathfce@kiit.ac.in

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ABSTRACT

This paper intends to investigate the effect of ground fly ash (GFA) on the mechanical properties of mortar. The ground fly ash was obtained by grinding raw fly ash in a mechanical ball milling up to 5 hours. The particle size of this GFA was in the range of micro to nano level. The mortar was prepared by adding GFA partially replacing ordinary Portland cement at the rate of 10%, 20%, 30% and 40% by weight of binder. Compressive strength and water absorption on mortar samples were investigated. The results reveal that the use of GFA to partially replace cement mortar was highly effective in improving the microstructure and mechanical properties of mortar. Compressive strength of cement mortars blended with 10 % micro/nano-flyash particles showed improved results by 10%, 24% & 34% than normal mortar samples after 28, 56 & 90 days of curing respectively and water absorption test proves that 10% ground blended mortar specimens absorbs 21% less water than that of other samples.

Key words: ground fly ash (GFA), mechanical ball milling, compressive strength, water absorption.

Introduction In recent years, ultrafine fly ashes have become one of the necessary ingredients of high-performance concrete. However,

many of the fly ashes are coarser, hence grinding is necessary to obtain sufficient higher performance in concrete.

In order to utilize the fly ashes effectively, the coarse portions of fly ashes have to be processed. Grinding can be a possible solution. It has been demonstrated that the compressive strength of concrete with fly ash can be improved by grinding [11], [12], [13] Paya et al claimed that, grinding improves the strength of fly ash mortars. They kept the W/CM constant. However, there is no information about the impact of grinding on consistency related flow values of mortars.

Kiattikomol et al. [14] reported five fly ashes from different origins. They ground fly ashes with three different finenesses. The substitution rate by weight was kept constant (20%). The consistency of mortars was also kept constant. Some ashes in raw form required more water than that of control mortar. The resultant strength values of fly ash incorporated mortars were also lower than that of control mortar. The higher water demand of some of these ashes has been attributed to their irregular shape and presence of porous particles. They concluded that fly ashes did not always improve the workability of mortar or concrete.

Depending on the quality and particle size of fly ash and the amount of cement replaced, fly ash may change the mechanical properties of concrete [2], [3], [4], [5], [6]. This change may be both positive and negative depending on many parameters. In addition to physical and chemical properties of fly ash, the most important parameters affecting the mechanical properties are the amount of substitution with cement and influence of fly ash on water demand for a desired workability.

The current research work encompasses the effect of ground-fly ash as partial replacement in cement paste and mortar. This paper emphasizes the realization and characterization of ground fly ash by mechanical ball milling process through XRD and SEM. This also evaluates the effects of ground fly ash on the consistency, setting time, compressive strength and water absorption properties of cement mortar.

EXPERIMENTAL PROCEDUREMaterials Used:

Cement: In this study, ordinary Portland cement (OPC) 43 grade with Blaine specific surface 300 m2/Kg was used. The chemical and physical compositions of cement are mentioned in Table 1.

Fine Aggregate: In the preparation of cement mortar mixes standard sand in accordance with IS: 650:1991, was used with

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cement and blended cement i.e. with ground fly ash in different proportions.

Water: Water used for the specimen preparation is free from impurities and having pH-7..

Fly ash: The fine particle of fly ash was collected from thermal power plant and added as a partial replacement to cement. The chemical and physical compositions or properties of fly ash are mentioned in Table 1.

Ground fly ash (GFA): In this paper an attempt was made to prepare ground sized fly ash from micro sized fly ash by mechanical ball milling. The

morphology of micro/ nano sized fly ash was mentioned in XRD and SEM as shown in fig 1 & 2.

Table 1. Chemical and physical properties of cement and fly ash.

Fig. 1. X-ray diffraction of 0, 5 & 10 hr ground fly ash

Fig.2 (a) Fig 2 (b) Fig 2 (c)

Fig 2. Cumulative % of particles passing of (a) Raw fly ash (b) 5 hr grinding & (c) 10 hr grinding FA

Materials

Chemical composition ( %) Physical properties

CaO SiO2 Al2O3 Fe2O3 SO3 Na2O K2O MgOLOI

(%)

Density

(g/cc)

Blain Area

(m2/kg)

Cement 63.5 20.3 2.2 1.8 2.1 0.45 0.35 1.1 1 3.15 300

Fly ash 1.3 54.41 30.40 8.44 0.1 1.0 1.98 1.53 - 2.1 350

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Fig. 3(a)

Fig.3 (b)

Fig. 3. SEM image of (a) raw fly ash (b) ground fly ash at 10 h milling

Mix Cement % GFA % Consistency %

Setting Time in

minutes

initial final

NC 100 0 30 153 230

N10 90 10 31 160 225

N20 80 20 32 166 230

N30 70 30 32 175 230

N40 60 40 33 190 255

Table. 3 Consistency, initial and final setting time of blended cement pastes

Mortar specimen: The cement was blended with ground fly ash in the proportions of 0%,10%, 20%, 30% and 40% by weight replacement of

cement and the ratio for mortar was taken as 1:3 (cement/ blended cement: standard sand). The nomenclature of the corresponding samples was given as NC for normal cement mortar and as N10, N20, N30 and N40 for 10%, 20%, 30%, and

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40% by weight replacements of cement mortar respectively. The mortar specimens are mentioned in the Table 3. The water was added to the blended cement as per IS code recommendation.

Consistency & Initial and final setting time tests: The consistency and setting time of fresh pastes were tested in accordance with IS: 4031:1988 part 4 and 5. The normal

consistency, initial and final setting time tests were conducted with the Vicat apparatus and shown in table no-3.

Compressive strength test:Mortar cube specimens of 70.6 x 70.6 x 70.6 mm were made for compressive strength in accordance with IS 4031 (Part 6)

1988. After 24 hours of casting, all specimens were kept in water for curing at room temperature (25 ± 50C) (25 +- 5 C) for 3, 7, 28, 56 and 90 days as per the recommendation of IS 4031-1988. The cube specimens were taken for compressive strength test using a compression testing machine under load control at 0.2 MPa/s.

Water absorption test:Three 70.6 mm cube samples of each mortar mix were taken for water absorption test. Saturated surface dry specimens

were put in a dry oven at 100°C for 48 h. After measuring the initial weight, specimens were immersed in water for 48 h. After taking out from water, the specimen was kept outside for one hour and then the final weight was measured and the absorption was calculated and reported in the Fig.6 to assess the permeability of mortar.

RESULTS AND DISCUSSIONConsistency and Setting time:

Due to increase of ground fly ash percentages the water demand increases with respect to percentage addition of ground fly ash as shown in table 3.

Structure and microstructure analysis:It was found from XRD for the 10 h milling, the crystallite size was reduced from 15 µm to 289 nm shown in Table 2 and Fig.

1. The size, shape and texture of the fresh as well as micro/nano structured ground fly ash were studied using Scanning Electron Microscopy (SEM). The high intensity peak of SiO2 at angle 26.58 degree diffraction peak reduces at 10h, it shows that the crystalline size reduces while milling in to smaller scale and it is also confirmed from the microstructure image shown in Fig. 1 & 3. Particle size distribution of different hours milling of fly ash was shown in Fig 2.

Compressive strength of mortar:The compressive strength results of cube specimens at 3, 7, 28, 56 and 90 days were mentioned in the Table 4.

The table shows the effect of ground fly ash addition with cement mortar on compressive strength of the hardened mortar. It was observed that the strength was improved in 10% replacement of ground fly ash and as on increase in GFA the strength gets decreasing.

Table 4. Compressive strength of mortar specimens Fig. 4 Compressive strength of blended cement mortars

Water Absorption Test:The absorption values of mortars were shown in fig. 5. It was clear that presence of pozzolanic material in cement mortar

decreased the water absorption value. Ground-FA was more effective in reduction of permeability than that of normal cement mortar. The following two phenomena can be distinguished for decreasing of permeability caused by using GFA: (i) Ground -FA particles generate a large number of C-S-H gel products on hydration and induce a more homogenous distribution of C-S-H and hence less pore structure. (ii) Ground -FA particles block the passages connecting capillary pores and water channels in cement paste. Water absorption was reduced as on adding of ground fly ash, for mortar mix N10, the percentage reduction of water absorption was 20%. Similarly for N20 specimens the percentage reduction of water absorption was found to be 8%.

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Fig. 5. Percentage of water absorption of mortar mixes.

CONCLUSIONThe following conclusions may be drawn from the obtained experimental data:

The peak of the GFA was having less height than the bulk fly ash as seen in XRD, it indicated that the size was reduced to less micron size - SEM Fig. 1 and 3.

On adding ground fly ash the water demand increased and similarly the water demand increases with respect to addition of micro/ nano fly ash.

The compressive strength of the N10 was found to be highest with respect to other GFA blended cement samples as mentioned in Table 4. With the addition of GFA to cement the blended mortar samples improved their strength characteristics. At 10% GFA the strength was improved by 10%, 24% & 34% than normal mortar samples after 28, 56 & 90 days of curing respectively.

Percentage of water absorption of N10 blended mortar specimen is less by 21% than that of other samples.Samples with higher percentage of GFA showed less refinement of the pore structure which lead to reduced strength.

REFERENCE 1. Monica J. Hanus, Andrew T. Harris. Nanotechnology innovations for the construction industry. Prog Mater Sci 2013;58:

1056–1102

2. Konstantin Sobolev, Ismasel Flores, Roman Hermosillo, Leticia M. Torres-Martinez, Nanomaterials and Nanotechnology for High-Performance Cement Composites, Proceedings of ACI Session on “Nanotechnology of Concrete: Recent Developments and Future Perspectives”,2006; 91-118.

3. T.M. Mendes, D. Hotza , W.L. Repette. Nanoparticles In Cement Based Materials A Review. Rev Adv Mater Sci 2015;40: 89-96.

4. Sri Tudjono, Purwanto, KartikaTrishnaApsari. Study the effect of adding nano fly ash and nano lime to compressive strength of mortar. Proc Eng 2014; 95: 426-32.

5. Prince Arulraj G., Jemimah Carmichael M. Effect of nano-fly ash on strength of concrete. International Journal of Civil and Structural Engineering. 2011;2(2) 475-482.

6. Her, Jae-Won Lim, Nam Gi. Physical and Chemical Properties of nano-slag mixed mortar. J. Korea Institute of Building Construction 2010; 10(6): 145-54.

7. Sharmila P., Dhinakaran G. Influence of nanoslag on micro structure, capillary suction and voids of high strength concrete. International Journal of Chem Tech Research 2014;6(4): 2521-28.

8. Ye Qing, Zhang Zenan, Kong Deyu, Chen Rongshen. Influence of nano-SiO2 addition on properties of hardened cement paste as compared with silica fume. Constr and Build Mater, 2007;21:539-45.

9. M. Stefanidou, I. Papayianni. Influence of nano-SiO2 on the Portland cement pastes. Composites: Part B 2012;43:2706-10.

10. G. Reddy Babu. Effect of nano-silica on properties of blended cement. International Journal of computational Engineering Research, 2013;3:50-55.

11. M.R. Jones, A. McCarthy, A.P.P.G. Booth,” Characteristics of the ultrafine component of fly ash”. Fuel, 85 (2006), pp. 2250–2259.

12. P. Chindaprasirt, S. Homwuttiwong, V. Sirivivatnanon,” Influence of fly ash fineness on strength, drying shrinkage and sulfate resistance of blended cement mortar. Cem Concr Res 34 (2004), pp. 1087–1092.

13. J. Paya, J. Monzo, M.V. Borrachero, E. Peris-Mora, F. Amahjour,” Mechanical treatment of fly ashes. Part IV. Strength development of ground fly ash–cement mortars cured at different temperatures”. Cem Concr Res, 30 (2000), pp. 543–551.

14. K. Kiattikomol, C. Jaturapitakkul, S. Songpiriyakij, S. Chutubtim,” A study of ground coarse fly ashes with different fineness from various sources as pozzolanic materials”. Cem Concr Compos, 23 (2001), pp. 335–343.

Feedback from Construction professionals

VTV Constructions, Bangalore

We wish to place on record that we have used RAMCO Cement in our various projects and found the product to be satisfactory and better as compared to other brands. Your Ramco Cement results are also very good. We are happy with service & quality. The service of your team member – Mr. SharanaBhasava is found to be good.

Umashankar.S

Mr Suresh , ISRO Layout , Bangalore

I am constructing my own building . Mr Yeshwant approached me and spoke about RAMCO Cement’s quality and technical services.

Later Mr. Yeshwant came along with Mr. Dinesh and conducted comparison tests. Ramco achieved higher strength and since then I started using RAMCO.

I am really happy with the service provided by MACE team . They attended the concreting and guided me by giving good technical advice and also rebound test few weeks later.

They visit my site very often and support me to build confidence.

Mr. Prashant .G, Bangalore

I have been working with Mr. Dinesh , Engineer , RAMCO Cements for a couple of months. I would like to share my experience of working with him and the good quality service he has been rendering. I being a small scale builder involved with constructions of Residential /Commercial establishments was comfortable using several brands of cement , however , Mr Dinesh met me a couple of times , educated and convinced me of the services rendered by RAMCO Cements .

With his support and service I started using Ramco for my ongoing project while Mr. Dinesh helped me in giving timely education to my site personnel about the best practices for RCC & PCC applications.

He has helped me to get the samples tested which helps me in convincing my customers about the quality of cement.

Brigade Projects, Bangalore

Greetings From BCV Team Precast !!!

We are pleased to inform that we have successfully completed the Third Precast Structure - Cedar Block (480 Flats) @ Brigade Orchards in record time of 10 months.

A sincere thanks to each & every one for your Extended Support.

Hope same support will be continued for our Upcoming Projects Juniper & Ivory.

Prompt Builders, Chennai

We have been engaged in Construction Industry for the past 30 Years. We use construction materials only from reputed companies. We are using Ramco Cements in all our projects. Also we have used Ramco Ready mix concrete. We have been extremely satisfied with the quality of concrete and it gives immense satisfaction to us. Hence we have decided to use only Ramco Ready mix concrete .

Your Technical services Engineer Mr.Narayanamoorthy has explained about your company, quality, services which enabled us to associated with Ramco Cements . We express our sincere thanks to him and wish him to continue his good work in adding many more customers to your company.

Regards,S.G.Ramesh Kumar

Prompt Builders

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Indian Standard Codes on Cement – Major Revisions & Additions

References : IS 269 : 2015 ; IS 1489 ( Part 1) :2015 ; IS 16415 :2015

ORDINARY PORTLAND CEMENT – SPECIFICATION – IS 269 :2015

In this revision , the Indian Standard specifications pertaining to 43 and 53 grade Ordinary Portland Cement have been included which were previously covered separately in the Indian Standards , IS 8112 : 2013 ‘Ordinary Portland Cement 43 grade – Specification ‘ and IS 12269:2013 ‘Ordinary Portland Cement 53 grade specification ‘ , respectively . IS 8112 and IS 12269 shall stand withdrawn subsequently.

PORTLAND POZZOLANA CEMENT – SPECIFICATION – IS 1489 ( Part 1 ) :2015

Minimum limit of Insoluble Residue has been included

Requirement of testing the cement at the earliest but not later than 3 months since the receipt of sample of testing, has been included .

Requirement of marking the ‘best before date ‘of cement has been introduced.

COMPOSITE CEMENT – SPECIFICATION – IS 16415 : 2015

A new code for Composite Cement has been introduced.

Composite Cement is an intimately interground mixture of Portland Cement Clinker , granulated slag and flyash with the addition of gypsum or an intimate and uniform blending of Ordinary Portland Cement , finely ground granulated slag and fine flyash.

For more details , Construction Professionals are advised to refer the respective codes on Ordinary Portland Cement ( IS 269 – 2015) , Portland Pozzolana Cement ( IS 1489 Part 1 2015) , Composite Cement ( IS 16415- 2015) available at Bureau of Indian Standards

RAMCO Ready Mix Concrete

Value Added Product from RAMCO Ready Mix Concrete – M15 Screed with PPC and Recron 3S fibre supplied to customer – M/s Samson Rubber Industries Pvt Ltd

FAQ‘sWhat is Cement?

Cement is an adhesive material with principal constituent as lime capable of bonding together solid particles

Can you list the different types of cement generally used?

Portland Pozzolana Cement (Fly Ash based), Ordinary Portland Cement (33, 43, 53 grades), Portland Slag Cement, Composite Cement, Rapid Hardening Portland Cement, Sulphate Resisting Portland Cement

What are the types of cement commonly available in our country?

Portland Pozzolana Cement (Fly Ash based) and Portland Slag Cement

What is Ordinary Portland Cement?

Ordinary Portland Cement is an adhesive material containing lime, silica, alumina and iron oxide. It is manufactured by heating these ingredients together to a very high temperature and grinding the resultant hard mass called clinker with gypsum.

What are blended cements?

Cements derived by mixing together clinker with gypsum and mineral admixtures like Fly Ash and / or Slag are called blended cements.

What is PPC?

PPC is Portland Pozzolana Cement manufactured using clinker, gypsum and fly ash.

What is PSC?

PSC is Portland Slag Cement manufactured using clinker, gypsum and slag.

What are the standards for blending materials like fly ash and slag?

Bureau of Indian Standards (BIS) has laid down the following standards for fly ash and slag

Fly Ash : IS 3812 Slag : IS 12089

What is Concrete?

Concrete is the resultant hardened product obtained by mixing cement, sand, aggregates and water in specified proportions, capable of taking compressive stresses or loads. In some cases, chemical admixtures are also added.

Are there different grades of concrete?

Yes there are different grades of concrete based on required compressive strength. M20, M30 and M40 are the normally used grades of concrete. M20 means that the concrete can take on a minimum compressive strength of 20MPA (Newton/sq.mm) after 28 days.

What is workability of concrete and how can it be measured?

Workability is the ease with which concrete can be mixed, placed and compacted. The common method of measuring workability at site is through the slump cone test.

What are the factors to be kept in mind while executing concrete work at site?

1. Form work should be done in a rigid way so as to withstand all types of loads

2. It is highly recommended to design the mix for the required compressive strength

3. Proper monitoring with special emphasis on water:cement ratio and required workability is a must during concrete preparation

4. Adequate cover should be given to the reinforcement bars to prevent corrosion

5. Vibrators must be used for compaction

What are the tips for curing of concrete?

1. Concrete must be kept in moist condition for a minimum of 10 days.

2. Ponding with wet gunny bags or suitable curing compounds are necessary to control evaporation

What are the factors affecting durability of concrete?

1. Free lime in cement : Lime present in cement as Calcium Oxide on hydration becomes hydrated free lime. Higher free lime reduces the durability of concrete. This is generally higher in Ordinary Portland Cement (OPC) whereas in blended cements like PPC and PSC, secondary gel reactions take place between fly ash/slag and hydrated lime, densifying the cement paste thereby making the concrete impermeable

2. Heat of hydration : The heat generated during hydration of cement is called heat of hydration. If this is high, it can lead to thermal shrinkage thereby causing cracks. OPC has higher heat of hydration as compared to blended cements like PPC and PSC.

TECH MANTRA

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