[理学]材料概论 双语 第五章 水泥.ppt

5.1 Portland Cement and Its Major Constituent Phases 5.1.1 Portland Cement General 5.2Getting Acquainted with Concrete Getting Acquainted with Concrete Properties Desired in Fresh or Plastic Concrete Properties Desired in Hardened Concrete Properties of Concrete Variables That Influence Concrete Quality Consumer Product Safety Properties Desired in Fresh or Plastic Concrete Although freshly mixed concrete is plastic for a short time only ,certain properties are desired at this stage because they affect the quality and cost of the hardened concrete. Properties Desired in Hardened Concrete Hardened concrete should be durable, strong, watertight and resistant to abrasion. All of these properties are influenced by the quality of the Portland cement paste. Properties of Concrete Freshly mixed concrete can be formed into practically any shape. Concrete can withstand heat and fire. While it can lose strength when the temperature high enough. Concrete resists vermin, termites and rodent. Variables That Influence Concrete Quality Water-cement Ratio Aggregate Gradation Air Entrainment Consumer Product Safety Prolonged contact between wet cement and concrete mixtures should be avoided. Contact with freshly mixed cement, mortar, grout ,or concrete may cause skin irritation or burns. Keep all cement and concrete mixtures and products out of small children. 5.3 Concrete：Strength and Behavior Cencrete materials are widely used in our daily life such as buildings, bridges, sidewalks. Strength is an important indicator to assess the common types of concrete hardening properties 1.impression，tension，shear and so on are the influence on the load-carrying capacity of both plain and reinforced structures 2.It is most easily to determine the concerning strength 3. The result of strength tests can be used as qualitative indications of other properties of hardened concrete Uniaxial Behavior Compression Strength And Tension Strength The typical stress-strain（应力-应变