A Presentation on

“BITUMEN MIXES FOR ROAD”

ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE

Submitted By:Nikhil Awana10EAYCE073

Submitted To:-Dr. Sheetal AgrawalHOD Civil Department

INTRODUCTION

As per Das et al.(2004); During 1900’s, the bituminous paving technique was first used on rural roads The term ‘foamed asphalt’ refers to a mixture of pavement construction aggregates and foamed bitumen. The foamed bitumen, or expanded bitumen, is produced by a process in which water is injected into the hot bitumen, resulting in spontaneous foaming. The bituminous mix design aims to determine the proportion of bitumen, filler, fine aggregates, and coarse aggregates to produce a mix which is workable, strong, durable and economical.

Asphaltic/Bituminous concrete consists of a mixture of aggregates continuously graded from maximum size , typically less than 25 mm, through the fine filler that is smaller than 0.075 mm. Sufficient bitumen is added to the mix so that the compacted mix is effectively impervious and will have acceptable dissipative and elastic properties.

Sufficient bitumen to ensure a durable pavement. Sufficient strength to resist shear deformation under traffic at higher temperature. Sufficient air voids in the compacted bitumen to allow for additional compaction by

traffic.   Sufficient workability to permit easy placement without segregation.   Sufficient resistance to avoid premature cracking due to repeated bending by traffic.   Sufficient resistance at low temperature to prevent shrinkage cracks.

OBJECTIVES OF BITUMINOUS MIX DESIGN

Requirements of Bituminous mixes

Stability Durability Flexibility Skid resistance Workability Desirable

properties

Coarse aggregate (retained on 2.36mm sieve) Fine aggregate (passing 2.36mm sieve but retained on 75m) Filler (passing 75m), may be cement. Binder: Bitumen etc.

CONSTITUENTS OF BITUMEN MIX

DEFINITIONS

Binder: A material used to hold solid particles together, i.e. bitumen or tar. Bitumen: A heavy fraction from oil distillation (also occurs as part of natural asphalt). Tar: A viscous liquid obtained from distillation of coal or wood.Rarely

used in construction currently in the UK. Asphalt: A mixture of bitumen and mineral filler.Note that Hot Rolled

Asphalt is a road surfacing material. Mastic: An adhering asphalt which is placed with trowelling. Macadam: A road construction material with binder and coarse

aggregate. Tarmacadam was the first road surfacing material.

ROAD CONSTRUCTION TYPES

Wearing Course

Base Course

Roadbase

Sub-Base Sub-Base

Wearing Course

Subgrade(limestone)

Lower Base (Crack Resistant)

roadbase

Subgrade(limestone)

BITUMINOUS CONSTRUCTION PROCEDURES

Surface Dressing Grouted Or Penetration Macadam Built-up Spray Grout Bitumen Bound Macadam Bituminous Carpet Bituminous Concrete

ASPHALT CONCRETE OR (BITUMINIOUS MIXTURE) Asphalt concrete is a composite material commonly used in construction projects such as road

surfaces, airports and parking lots. It consists of asphalt (used as a binder) and mineral aggregate mixed together

Hot mix asphalt concrete (commonly abbreviated as HMAC or HMA) is produced by heating the asphalt binder to decrease its viscosity, and drying the aggregate to remove moisture from it prior to mixing

Warm mix asphalt Concrete (commonly abbreviated as WMA) is produced by adding either zeo-lites waxes, asphalt emulsions, or sometimes even water to the asphalt binder prior to mixing

Cold mix asphalt concrete is produced by emulsifying the asphalt in water with (essentially) soap prior to mixing with the aggregate

Cut-back asphalt concrete is produced by dissolving the binder in kerosene or another lighter fraction of petroleum prior to mixing with the aggregate.

Mastic asphalt concrete or sheet asphalt is produced by heating hard grade blown bitumen (oxidation) in a green cooker (mixer) until it has become a viscous liquid after which the aggregate mix is then added.

Natural asphalt concrete can be produced from bituminous rock, found in some parts of the world, where porous sedimentary rock near the surface has been impregnated with upwelling bitumen.

HOT MIX ASPHALTHMA is a mixture of coarse and fine aggregates and asphalt binder. HMA, as the name suggests, is mixed, placed and compacted at higher temperature.

Dense-Graded MixesThis type of bituminous concrete is a well-graded HMA has good proportion of all constituents are also called Dense bituminous macadam.

Dense graded HMA surface

Dense graded core sample

Stone Matrix Asphalt (SMA) Stone matrix asphalt (SMA), sometimes called stone mastic asphalt, is a gap-graded HMA originally developed in Europe to maximize rutting resistance and durability in heavy traffic road.

SMA Lab Sample SMA Surface Open-Graded Mixes

Unlike dense-graded mixes and SMA, an open-graded HMA mixture is designed to be water permeable.Open-graded mixes use only crushed stone (or gravel) and a small percentage of manufactured sands

CHARACTERISTICS OF MATERIAL USED IN BITUMINOUS MIX

Mineral AggregateObtained from different natural sources such as glacial deposits or mines.

A highly cubic shape and rough texture to resist rutting and movements. A hardness which can resist fracturing under heavy traffic loads. A high resistance to polishing, and A high resistance to abrasion.

Mineral filler Generally filler plays an important role in properties of bituminous mixture particularly in terms of air voids, voids in mineral aggregate. Different types of mineral fillers are used in the SMA mixes such as stone dust, ordinary Portland cement (OPC), slag cement, fly Ash, hydrated lime etc

Binder Bitumen acts as a binding agent to the aggregates, fines and stabilizers in bituminous mixtures. Binder provides durability to the mix. Stabilizing Additives The main stabilizing additives used in mixes can be classified in to different groups;  Fibres’ (Cellulose Fibres, Mineral Fibres, Chemical Fibres) Polymer Powder and flour like materials (Silicic acid, Special Filler)  Plastics (Polymer Powders or Pellets)   Natural fiber:-Natural fiber classified into 3 category depending upon the part of plant

from where it is extracted  Stem fiber (jute, banana etc.)  Leaf fiber (sisal, pineapple)  Fruit fiber (cotton, coir, oil palm)

Conventional Bituminous Mix Technologies

Hot Mix Technologies-Shortfalls

Heating of binder at 150-170°C Heating of aggregates at 185-200°C Production at 150-160°C Laying at 140°C Compaction at 120 °C Environmental pollution High energy consumption Limited work year

Solution…!!!Cold mix technologies using bitumenemulsion as binder

COLD BITUMINOUS MIXES

Cold mix technology eliminates heating of aggregates, bitumen binder, uses cationic bitumen emulsions.  Optimized composition of open graded premix carpet, semi- dense bituminous concrete, microsurfacing and bituminous macadam .

It is environment friendly, offer greater social acceptance, increased paving period, acceptable performance and cost effective.

 Technology has found wide acceptance.

PRODUCTION OF COLD MIXES

Adding Pre-mix Water Adding Emulsion In Drummixer

Cold mix on coneyer belt Discharge of cold to dumper

PREPARATION OF COLD MIX

Charging of Aggregates Wetting of Aggregates

Emulsion for Cold Mix Discharging of Cold Mix

Transportation of cold mix  Cold mix shall be discharged in trolleys/wheel barrow  Cold mix shall be transported to site by wheel barrow/tippers  Avoid newly laid surface or tacky road surface while ferrying  Spreading of cold mix  Spread cold mix in half the road-width  Required thickness with spreader Cold mix turned black from brown  Cold mix aerated for about one hours

 Compaction  Compacted with 8-10 ton road roller  Wetting of wheels

Preparation of Marshall Specimens1100g Blended Aggregates 4 % water content Mix for wettingAddition of emulsion 7,8,9% intoaggregates Mixing for uniformcoating Cold mix in mouldCompaction with 75 Blows oneach face Specimens MarshallSpecimen Curing for 3 days at400C Testing for Bulk Density,Stability, flow , Retained Stab. at 250C

TESTING OF COLD MIX

APPLICATIONS OF BITUMEN EMULSIONS

Tack coat & priming Crack filling and sealing Repair of pot- holes & depression Surface dressing Premix Carpet Bituminous Macadam Microsurfacing Repair of utility cuts

Thank you