Chapter 9Chapter 9

§ 9.1 Introduction9.1 Introduction

WWhat is Bituminous Concrete hat is Bituminous Concrete Definition of Bituminous MixtureDefinition of Bituminous MixtureClassifications of Bituminous MixtureClassifications of Bituminous MixtureCharacteristics of Bituminous MixtureCharacteristics of Bituminous Mixture

WWhat is hat is ““Bituminous Concrete Bituminous Concrete ””

• Bituminous mixture is the admixture material mixed with mineral and bituminous.

• Mineral (mineral aggregate, mineral mixture) + Bituminous → Bituminous mixture → Spreading, Compacting → Bituminous concrete (AC) or Bituminous macadam (AM)

Bituminous Bituminous ConcretConcret

ee

Bituminous Bituminous ConcretConcret

ee

Binding Binding MediumMedium

Binding Binding MediumMedium

BituminousBituminous MixtureMixture

BituminousBituminous MixtureMixture

CompactingCompactingCompactingCompacting

SpreadingSpreadingSpreadingSpreading

Mineral Mineral AggregateAggregateMineral Mineral AggregateAggregate

Definition of Bituminous Mixture

Bituminous mixture is an excellent pavement material mixed with mineral, appropriate gradation and bituminous.

MineralMineral

BituminousBituminousBituminous mixtureBituminous mixture

Sketch Map of Bituminous Mixture

Classifications of Bituminous MixtureClassifications of Bituminous Mixture

Bituminous Mixture

Coal bituminous mixture

Petroleum bituminous mixture

Bituminous

There are petroleum bituminous mixture and coal bituminous mixture by types of bituminous.

Bituminous MixtureBituminous MixtureBituminous MixtureBituminous Mixture

Hot-mixed and cool-spreadHot-mixed and cool-spreadHot-mixed and cool-spreadHot-mixed and cool-spread

Hot-mixed and hot-spreadHot-mixed and hot-spreadHot-mixed and hot-spreadHot-mixed and hot-spread

Construction Temperature

Construction Temperature

Cool-mixed and cool-spreadCool-mixed and cool-spreadCool-mixed and cool-spreadCool-mixed and cool-spread

Classifications of Bituminous MixtureClassifications of Bituminous Mixture

Fig.9.1.1 Spread construction

There are hot-mixed and hot-spread, hot-mixed and cool-spread cool-mixed and cool-spread by construction temperature

Bituminous MixtureMaximum Particle

Diameter

Coarse gradeDmax=37.5 ,31.5mm

Special coarse gradeDmax=53mm

Special coarse gradeDmax=53mm

Medium gradeDmax=26.5,19mm

Fine gradeDmax=16, 13.2,

4.75mm

Classifications of Bituminous MixtureClassifications of Bituminous Mixture

图 9.1.2 Sieve for particle

There are special coarse grade, coarse grade, medium grade and fine grade by maximum particle diameter.

Bituminous MixtureBituminous Mixture

DiscontinuousDiscontinuous

ContinuousContinuous

Mineral GradationMineral Gradation

Classifications of Bituminous MixtureClassifications of Bituminous Mixture

There are continuous mixture and discontinuous mixture by mineral gradation.

Bituminous MixtureBituminous Mixture

Admixture material

compactness or the

residual porosity

after pressure

Admixture material

compactness or the

residual porosity

after pressure

Dense gradationDense gradation(p(p ＜＜ 10%)10%)

Dense gradationDense gradation(p(p ＜＜ 10%)10%)

Half open-gradationHalf open-gradation(p(p ＞＞ 10%)10%)

Half open-gradationHalf open-gradation(p(p ＞＞ 10%)10%)

Open-gradationOpen-gradationpp ＞＞ 15%15%

Open-gradationOpen-gradationpp ＞＞ 15%15%

Density type Ⅰ 3%~6%

Density type Ⅰ 3%~6%

Density type Ⅱ 4%~10%

Density type Ⅱ 4%~10%

Classifications of Bituminous MixtureClassifications of Bituminous MixtureThere are four kinds of gradation dense gradation, half open-There are four kinds of gradation dense gradation, half open-gradation and open-gradation, discontinuous mixture. They gradation and open-gradation, discontinuous mixture. They are classified by admixture material compactness or the are classified by admixture material compactness or the residual porosity after pressure.residual porosity after pressure.

Characteristics of Bituminous MixtureCharacteristics of Bituminous Mixture

Good performance in viscosity-elasticity-plasticity, mechanical property, high temperature stability and hypothermia flexibility

High security Convenient construction Economic and enduring uses Recycling uses

Hot-mixed and Hot-spread Hot-mixed and Hot-spread Bituminous MixtureBituminous Mixture

• It is a sort of bituminous mixture which is used most widely and typically

• Widely used in engineering

• We will study this kind of mixture in details