OPPORTUNITIES FOR RESEARCH

IN

CEMENT & BUILDING MATERIALS

Dr J D BAPAT

DEPARTMENT OF TECHNOLOGY (DOT)

SAVITRIBAI PHULE PUNE UNIVERSITY

17 OCTOBER 2014

WHY AM I TALKING ABOUT

CEMENT & BUILDING MATERIALS

STARTED CARRIER AS SCIENTIST AT

NATIONAL COUNCIL FOR CEMENT AND

BUILDING MATERIALS (NCB), NEW DELHI,

39 YEARS BACK (1975)

RESEARCHED IN AREAS OF ENERGY,

ENVIRONMENT, USING INDUSTRIAL &

AGRICULTURAL WASTES IN CEMENT &

CONCRETE

STILL CONTINUE TO WORK IN THE AREA

RAW MATERIALS & FUELS

LIMESTONE & CLAY AS THE SOURCE

OF CALCIUM, SILICON, ALUMINUM &

IRON

MOSTLY MINERAL COAL IN FINELY

GROUND FORM

ALTERNATIVE SOLID FUELS

• REFUSE DERIVED FUEL (RDF), TIRE-DERIVED FUEL (TDF), MEAT & BONE MEAL (MBM), WASTE WOOD, SEWAGE SLUDGE, PAPER & PLASTICS

• FEEDING THROUGH ROTARY KILN OR MIXING WITH RAW MATERIALS

• REQUIRES NEW COMBUSTION EQUIPMENT OR MODIFICATION OF EXISTING KILN SYSTEMS

• ALTERNATIVE FUELS INFLUENCE PROCESS STABILITY & PRODUCT QUALITY

• DEPOSIT FORMATIONS IN THE ROTARY KILN MATERIAL INLET END, KILN RISER DUCT & LOWER CYCLONE STAGES

• CLINKER QUALITY MAY ALSO BE AFFECTED BY MINOR COMPOUNDS FROM FUEL ASHES OR FROM UNBURNED CARBON LEAVING ROTARY KILN WITH CLINKER

BURNING WASTE FUELS

Wood Chips

REPLACING PORTLAND

CEMENT

PRODUCTION OF ONE t OF PORTLAND CEMENT

EXPELS ALMOST EQUAL MASS OF CO2 IN

ATMOSPHERE

CEMENT INDUSTRY CONTRIBUTES 5% OF THE

TOTAL ANTHROPOGENIC CO2 EMISSIONS

GLOBALLY

MINERAL ADMIXTURES (MA) REPLACE CEMENT &

AFFECT REDUCTION IN CO2 EMISSION

THEY ARE INDUSTRIAL & AGRICULTURAL

WASTES

VOLUME OF THESE WASTES CURRENTLY

PRODUCED WORLDWIDE EXCEEDS THEIR

UTILIZATION

RICE HUSK ASH (RHA)

RH IS PRESENTLY CONSIDERED AS

AGRICULTURAL WASTE & USED AS FUEL,WHERE

ITS POZZOLANIC VALUE LIES UNUTILIZED

ABUNDANT AVAILABILITY OF RH IN RICE

PRODUCING COUNTRIES PROVIDES HUGE SCOPE

TO RECOVER ITS HEAT VALUE TO GENERATE

POWER & TO USE RHA PRODUCED IN CEMENT &

CONCRETE

LARGE-SCALE APPLICATION OF RHA IN THE

CONSTRUCTION INDUSTRY REQUIRES INDUSTRIAL

& ECONOMIC POLICY PLANNING

RICE HUSK ASH (RHA)

PHYSICAL & MINERALOGICAL CHARACTERISTICS OF RHA:

AMORPHOUS SILICA, SURFACE AREA, GRINDABILITY & CARBON CONTENT,

DEPEND UPON TEMPERATURE, ENVIRONMENT & DURATION OF COMBUSTION

SURFACE SILANOL (SI-OH) SITES IN THE AMORPHOUS SILICA

RESPONSIBLE FOR THE POZZOLANIC ACTIVITY OF RHA

TO OBTAIN SILICA IN AMORPHOUS FORM, COMBUSTION TEMPERATURE

REMAINS IN 500°C–700°C, WITH OPTIMUM TIME DURATION APPROPRIATE FOR

THE PROCESS, TO OBTAIN RHA WITH LOW CARBON CONTENT, HIGH SURFACE

AREA & MAXIMUM GRINDABILITY

MODERN FLUIDIZED OR CYCLONIC BED PROCESSES PRODUCE RHA WITH

ABOVE 85% AMORPHOUS SILICA AND VERY LOW CARBON CONTENT IN RANGE

OF 1%–4%

NEED TO IDENTIFY A PROCESS TO MANUFACTURE RHA ON A SMALL SCALE

NEAR PADDY FIELDS & SUITABLE FOR ADOPTION IN THE RURAL AREAS

RICE HUSK ASH (RHA)

RHA, PRODUCED UNDER PROPER CONDITIONS, IS SOFT &

EASILY PULVERIZED TO DESIRED SIZE, FINER THAN CEMENT,

WITH PARTICLE SIZE < 10 MICRON & BET SURFACE AREA OF

20–40 m2/g, IN COMPARISON SF: > 15 M2/g

SILICA CONTENT (MOSTLY AMORPHOUS): 87-96%

UNLIKE SF OR FA, PARTICLES OF RHA ARE ANGULAR &

REMAIN POROUS EVEN AFTER SIZE REDUCTION

IMPROPERLY GROUND RHA EXHIBITS LOW POZZOLANIC

ACTIVITY & HIGH WATER REQUIREMENT DUE TO WATER

ABSORPTION BY POROUS PARTICLES

FINE PARTICLES OF RHA AFFECT REFINEMENT IN PORE

STRUCTURE OF CONCRETE

USE OF RHA IN CONCRETE CAN BE CONSIDERED AS SAFE FROM

TOXICITY POINT OF VIEW

CEMENT REPLACEMENT UP TO 30% REPORTED

PORTLAND LIMESTONE

CEMENT (PLC)

PORTLAND LIMESTONE

CEMENT (PLC)

IMPROVED PARTICLE PACKING

PROVIDES NUCLEATION

SITES FOR HYDRATION PRODUCTS

LS REACTS WITH ALUMINATES IN CEMENT TO FORM CARBOALUMINATES

PORTLAND LIMESTONE CEMENT (PLC)

LIMESTONE REQUIREMENTS: EN STANDARDS

CALCIUM CARBONATE > 75%

TOTAL ORGANIC CARBON (TOC): MAX 0.5%

CLAY: MAX 1.2 g/100g

PORTLAND HIGH VOLUME

FLY ASH CEMENT (PHFC)

PHFC REFERS TO BLENDED CEMENT PRODUCED IN CEMENT PLANT, WITH FA REPLACEMENT CEMENT >55%

AT PRESENT HIGH VOLUMES OF FA (>55%) ARE ADDED AS REPLACEMENT OF CEMENT, AT RMC PLANTS, TO PRODUCE HIGH VOLUME FLY ASH CONCRETE (HVFAC) (.) IT NECESSITATES ADDITIONAL STORAGE SILOS & QUALITY CONTROL AT JOB SITE

PHFC IS ONE OPTION, INCREASING AMOUNT OF FA THAT CAN REPLACE PORTLAND CEMENT (PC) FROM <20% IN CONVENTIONAL MIXES UP TO AS HIGH AS 55%

PHFC CAN BE PRODUCED EITHER BY INTER-GRINDING FA WITH PC CLINKER & GYPSUM OR BY BLENDING DRY FA WITH PC (.) SOMETIMES DRY SUPER PLASTICISER IS ALSO INTERGROUND (.) PRODUCTION OF PHFC USING INTER-GRINDING METHOD APPEARS MOST COST-EFFECTIVE & PRACTICAL

REQUIRED TO SATISFY MINIMUM STRENGTH AS PER ASTM C1157, OF 10 & 17 MPa AT 3 & 7 DAYS RESPECTIVELY

PORTLAND HIGH VOLUME FLY ASH

CEMENT (PHFC)

CONCRETE WITH PHFC

RESULTS OF LABORATORY TRIALS ON PHFC WITH 55% FA*

FRESH CONCRETE: CONCRETE WITH PHFC REQUIRED MORE SP & AEA, AS INTER-GRINDING INCREASED FINENESS

COMPRESSIVE STRENGTH: IRRESPECTIVE OF SOURCE & TYPE OF FA, CONCRETE WITH PHFC DEVELOPED BETTER STRENGTH COMPARED TO THAT PREPARED BY SEPARATE ADDITION OF CEMENT & UN-GROUND FA AT MIXER

CHLORIDE RESISTANCE: INTER-GRINDING IMPROVED CHLORIDE RESISTANCE OF CONCRETE

*Ref: “Development of high-volume fly ash blended cements”, Electric Power Research Institute (EPRI), California, USA, 2001

PORTLAND HIGH VOLUME

FLY ASH CEMENT (PHFC)

PHFC IS FACTORY MADE WITH FA REPLACING CEMENT AT 55%

ADDING SP TO CLINKER AT FINISH GRINDING STAGE HELP REDUCE GRINDING ENERGY & ALSO SOLVES COMPATIBILITY ISSUES AT CONCRETING STAGE

INTER-GRINDING FA WITH GROUND CEMENT FOR FIXED TIME PERIOD IMPARTS BETTER CONCRETE PROPERTIES

PHFC HAS VERY GOOD RESISTANCE TOWARDS CHLORIDE PENETRATION

NEW MINERAL ADMIXTURES

UNDER INVESTIGATION

ASH PRODUCED FROM BIOMASS

CORN COB ASH (CCA)

PALM OIL RESIDUE ASH (PORA)

SUGARCANE BAGASSE ASH (SBA)

WHEAT STRAW ASH (WSA)

WOOD WASTE ASH (WWA

SEWAGE SLUDGE ASH (SSA)

MUNICIPAL SOLID WASTE ASH (MSWA)

NEW MINERAL ADMIXTURES

UNDER INVESTIGATION

BIOMASS ASH

UP TO 20%, OF BIOMASS CONSISTS OF INORGANIC CONSTITUENTS, REFERRED AS ASH, WHICH CANNOT BE CONVERTED TO ENERGY

POSSIBLE TO PRODUCE PFA WITH POZZOLANIC PROPERTIES, BURNING & PROCESSING BIOMASS UNDER CONTROLLED CONDITIONS, EITHER THRU CO-FIRING WITH MINERAL COAL OR SEPARATELY

NECESSARY TO CONTROL THE CARBON, ALKALI, CHLORIDE & SULFATE CONTENT

IN ADDITION, LEACHING & TOXICITY PROPERTIES ALSO NEED TO BE TESTED BEFORE ITS USE IN CONCRETE

POSSIBLE TO PRODUCE STRUCTURAL GRADE CONCRETE, PARTIALLY REPLACING CEMENT WITH BIOMASS PFA TO THE EXTENT OF 20%–25%

WATER DEMAND, REQUIREMENT OF AIR ENTRAINING AGENT & SETTING TIME INCREASE WITH THE APPLICATION OF SUCH PFA

DURABILITY PARAMETERS ALSO NEED TO BE TESTED, ON A CASE-TO-CASE BASIS

STRATEGIES FOR SUSTAINABLE MANAGEMENT OF BIOMASS ASH WILL HAVE TO BE WORKED OUT, CONSIDERING DISPOSAL COST & VOLUME, INCREASING WORLDWIDE.

ASTM C618 PROHIBITS USE OF BIOMASS FLY ASH IN CONCRETE

EUROPEAN STANDARD ALLOWS CO-FIRING OF BIOMASS WITH COAL, UP TO 25% ON MASS BASIS

ON ACCOUNT OF WIDE RANGE OF BIOMASS RESOURCES & COMBUSTION CONDITIONS, UPPER LIMIT HAS BEEN SPECIFIED FOR THE CONTENT OF ALKALI (5%), CHLORIDE (0.1%) & UNBURNED CARBON (5%).

NEW MINERAL ADMIXTURES UNDER

INVESTIGATION

SEWAGE SLUDGE ASH (SSA)

TREATMENT OF WASTEWATER GENERATES SLUDGE & ITS INCINERATION PRODUCES SSA

ABOUT 300–400 kg ASH/t IS PRODUCED

SINCE SSA IS A WASTE MATERIAL, ATTENTION MUST BE PAID TO ENVIRONMENTAL IMPACT, WHEN REUSED

IN CONCRETE, REDUCED WORKABILITY & INCREASED SETTING TIME HAS BEEN REPORTED (.) NEGATIVE EFFECT CAN BE COUNTERED USING SUPERPLASTICIZER (.) RESULTS ON COMPRESSIVE STRENGTH ARE NOT UNIFORM

IN VIEW OF THAT, 10%–15% CEMENT REPLACEMENT MAY BE TRIED, SUBJECT TO THE SATISFACTORY LEACHABILITY TESTS

NEW MINERAL ADMIXTURES UNDER

INVESTIGATION

MUNICIPAL SOLID WASTE ASH (MSWA)

MILLIONS OF TONS OF MSW IS PRODUCED GLOBALLY (.) INCREASED ENVIRONMENTAL AWARENESS, CONTINUOUSLY INCREASING LANDFILL COSTS, SCARCITY OF LANDFILL SITES & SLOW COMPOST PROCESS UNDERLINE NEED TO TAKE INTO ACCOUNT ALTERNATIVE DISPOSAL METHODS

INCINERATION IS A COMMON TECHNIQUE & REDUCES SOLID WASTE BY MASS & VOLUME, PROVIDES FOR ENERGY RECOVERY & LEADS TO COMPLETE DISINFECTION

TOTAL AMOUNT OF MSWA GENERATION RANGES FROM 4% TO 10% BY VOLUME &15%–20% BY WEIGHT OF ORIGINAL QUANTITY OF WASTE & FLY ASH (OBTAINED FROM THE DUST COLLECTION EQUIPMENT) AMOUNTS TO 10%–20% OF TOTAL ASH

PORTLAND CEMENT, BLENDED WITH PFA & BFS, CONTAINING UP TO 20% MSWA, IS FOUND TO BE GOOD IN MECHANICAL PROPERTIES AS WELL AS FOR IMMOBILIZATION OF LEAD & SULFATE BUT SOMEWHAT LESSER FOR ZINC & CHLORIDE, INTO STABLE, LESS SOLUBLE COMPOUNDS (.) CAPACITY INCREASES WITH HARDENING AGE

ALTHOUGH MSWA CAN BE ADDED TO CONCRETE AS A PARTIAL CEMENT REPLACEMENT, THERE IS STILL SOME SCOPE FOR THE DEVELOPMENT, BEFORE IT COULD BE EFFECTIVELY USED AS A MINERAL ADMIXTURE

FLY ASH IN CONCRETE:

ACKNOWLEDGEMENT

• I THANKFULLY ACKNOWLEDGE THAT WHILE MAKING

THIS PRESENTATION, I HAVE FREELY DRAWN UPON

THE INFORMATION PUBLISHED IN THE FOLLOWING

BOOK:

MINERAL ADMIXTURES IN CEMENT AND CONCRETE

AUTHOR: JAYANT D. BAPAT

PUBLISHER: CRC PRESS, TAYLOR & FRANCIS GROUP,

USA

TRAINING COURSE

CONTENTS

APPLICATION OF MINERAL ADMIXTURES:

FA, BFS, SF, MK RHA

APPLICATION OF CHEMICAL ADMIXTURES

& SUPER PLASTICISERS

HIGH PERFROMANCE CONCRETE:

HIGH STRENGTH, SCC, RCC, LIGHTWEIGHT,

PERVIOUS, HVFAC

GROUP DISCUSSIONS, CASE STUDIES &

VIDEOS

DETAILS: http://www.drjdbapat.com

TRAINING COURSE

WHO SHOULD ATTEND

ENGINEERS WORKING AT CONSTRUCTION

SITE

ENGINEERS WORKING WITH CEMENT,

CONCRETE INDUSTRY

ENGINEERS WORKING WTH MANUFACTURERS

AND SUPPLIERS OF CHEMICAL ADMIXTURES

AND MINERAL ADMIXTURES

ENGINEERS WORKING ON PRODUCT

DEVELOPMENT

STUDENTS/RESEARCHERS

DETAILS: http://www.drjdbapat.com

TRAINING COURSE

FLEXIBILITY

CONTENTS: CHOOSE AS PER YOUR

REQUIREMENT

DURATION: 1-2 DAYS

VENUE: PUNE OR YOUR HEAD OFFICE,

PLANT OR CONSTRUCTION SITE

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NEW BLENDED CEMENTS

Thanks!!!