INVESTIGATION AND STATISTICAL ANALYSIS ON BASIC RESISTANCE PARAMETERS OF CONCRETE STRUCTURE

Taking the typical concrete buildings in Xi'an and Xianyang and their periphery county cities as research objects, more than 1 000 structures were investigated.The concrete strength, reinforcing bar properties and component dimension parameters were statistically analyzed.The influence of some factors such as preparation process, stirring method and construction level on material properties and dimension parameters were analyzed.The results show that the strength mean of commercial concrete is close to strength mean of self-mixing concrete, but the strength variation of commercial concrete is smaller.In addition to the concrete strength of floor is higher, the concrete strengths of other elements are basically the same.The higher the building company's qualification, the higher is the concrete strength and the smaller is the strength variation.Reinforcing bar properties are good and their performance difference of different manufacturers is not big.The control level of dominant geometric parameter is better, but the control level of hidden geometric parameter is poor and its variation is large.