Low Amount Of Cement Concrete Mechanical And Durability Tests

Nowadays, the demand of the cement concrete in the world grows explosively has caused the cement demand sharply increased either, but the cement production is consuming the huge energy, the resources consumption as a price, and causes a serious environment load. So, the research of how to reduce the cement content in the plain concrete as far as possible, and satisfy its durability appears especially important. It also has provided a brand-new path regarding the environmental protection and the architecture industry sustainable development.This paper has researched on the influence rules of cement content to the concretes compressive strength, the folding strength, the splitting tensile strength, the elasticity coefficient as well as the temperature rise; esepcially has studied the performance of carbonization and the anti-chloride permeability of the low cement content concrete. And carries on the analysis and discuss combining the theoretical calculation and the test result, then has used unified microscopic and chemistry test method to analyze the mortar and the concretes hole liquid phase alkalinity change rule, as well as carried on certain error analysis. The main achievement is obtained as follows:1. When fly-ash and slag powder are added in the multi-cement paste, the requirement of water increses, the mobility reduces, and the setting time lengthens obviously.2. The compressive strength, the folding strength, the splitting tensile strength of concrete as well as the internal temperature reduce along with the cement content reducing, but the effect of elasticity coefficient isn't evident. When the cementitious content is 250 kg/m~3, with 40% cement, the compressive strength is 33.6 MPa.3. When the cement content is from 100 to 340 kg/m~3, the reduction of cement content is quite remarkable for the performance of the carbonization at the early age, and the speed changes slow gradually later, but the reduction of cement content doesn't accelerate the speed of concrete carbonization. The chloride ion diffusion coefficient increses along with the total quantity of gelled materials reducing, but it doesn't increse along with the cement content reducing. When the cement content is 50 kg/m~3, the depth of concrete carbonization is 27mm at 28d. when the cement content is lower than 40% or 50 kg/m~3, the resistance to carbonization and chloride permeability reduces obviously.4. The hole liquid phase alkalinity in the cement mortar and the concretes reduces along with the reducing of the cement content, and the reduces scope is more big along with the time growing, the minimum concretes pH value achieved 11.77 at the 90d.