Chapter 9

§ 9.1 Introduction  What is Bituminous Concrete  Definition of Bituminous Mixture  Classifications of Bituminous Mixture  Characteristics of Bituminous Mixture

What is “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 Concret e Binding Medium Bituminous Mixture Compacting Spreading Mineral Aggregate

Definition of Bituminous Mixture  Bituminous mixture is an excellent pavement material mixed with mineral, appropriate gradation and bituminous. Mineral Bituminous Bituminous mixture Sketch Map of Bituminous Mixture

Classifications 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 Mixture Hot-mixed and cool-spread Hot-mixed and hot-spread Construction Temperature Cool-mixed and cool-spread Classifications of Bituminous Mixture Fig Spread construction There are hot-mixed and hot-spread, hot-mixed and cool- spread cool-mixed and cool-spread by construction temperature

Bituminous Mixture Maximum Particle Diameter Coarse grade D max =37.5,31.5mm Special coarse grade D max =53mm Medium grade D max =26.5,19mm Fine grade D max =16, 13.2, 4.75mm Classifications of Bituminous Mixture 图 Sieve for particle There are special coarse grade, coarse grade, medium grade and fine grade by maximum particle diameter.

Bituminous Mixture Discontinuous Continuous Mineral Gradation Classifications of Bituminous Mixture There are continuous mixture and discontinuous mixture by mineral gradation.

Bituminous Mixture Admixture material compactness or the residual porosity after pressure Dense gradation (p ＜ 10%) Half open-gradation (p ＞ 10%) Open-gradation p ＞ 15% Density type Ⅰ 3%~6% Density type Ⅱ 4%~10% Classifications of Bituminous Mixture There are four kinds of gradation dense gradation, half open- gradation and open-gradation, discontinuous mixture. They are classified by admixture material compactness or the residual porosity after pressure.

Characteristics 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 Bituminous 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