Design method and homogeneity control of bridge fair-faced concrete
Zhou Xiaojun, Mou Tingmin, Ding Qingjun and Nie Chuanzhen
DOI:10.11835/j.issn.1674-4764.2015.01.019
Received May 20, 2014,Revised , Accepted , Available online July 01, 2015
Volume ,2015,Pages 117-122
- Abstract
According to the structural characteristics of bridge engineering, the mix optimization design method of bridge fair-faced concrete was presented, and C30~C50 concrete with high cohesion and package, outstanding fluidity and excellent mechanical properties were prepared. Through the test of air content of fresh concrete, micro hardness and micro structure in different parts of hardened concrete specimens, effects of viscosity-modifying admixtures on homogeneity of concrete were discussed. The results showed that the composition of bridge fair-faced concrete were relatively homogeneous, and the microstructure were relatively dense. When C30 concrete mixed with 5 × 10 -5 cellulose ether or 6% silica fume (mass fraction of cementitious material), air content of fresh concrete were less than 2%, and slurry viscosity values were between 1 900 and 2 000 MPa·s. Also, the micro hardness values in different parts of hardened concrete specimens were closed. The results were applied in practical bridge engineering, which generally meets the apparent quality requirements of bridge fair faced concrete.