Testing And Numerical Simulation Of Thermal Expansion Coefficient For Rock-filled Concrete

Rock-Filled concrete (RFC) is a new type of massive concrete constructiontechnology, it is composed of large size rock and self-compacting concrete (SCC), andhas been applied to several projects due to its significant economic benefits and highconstruction speed. The coefficient of thermal expansion (CTE) is an important physicalparameter. Therefore, there is a lot of study on the CTE of concrete. However, the studyon the CTE of RFC is little so far. This paper studies the CTE of RFC through threeaspects: experimental test, numerical simulation and theoretical analysis.First, the CTE tests of rock, SCC and RFC are carried out and their CTE isobtained. Then the CTE variation of RFC with age is analyzed. In addition, the CTE ofRFC is compared with that of SCC. The CTE of large-size SCC sample is comparedwith that of the standard-size SCC sample.Secondly, a three-dimensional RFC model is built to simulate the process of CTEtest of RFC. The CTE of RFC obtained by numerical simulation is analyzed.Finally, by considering the RFC as a SCC-rock composite material, a formula forcalculating the CTE of RFC is deduced based on the elastic modulus and CTE of SCCand rock. The RFC CTE in different ages and different rock proportions is analyzed.The theoretical result is compared with the simulating and test result.The results show:(1) the size effect of SCC is little in the measuring CTE.(2) TheCTE of RFC is obviously lower than that of SCC because the CTE of rock is lower thanthat of SCC and the rock limit the thermal expansion of SCC.(3) The CTE of RFCincreases with age due to the increasing CTE of SCC and constant CTE of rock.However, the growth rate of the RFC CTE with age is lower than that of SCC.(4) Thesimulating results agree well with theoretical results. Meanwhile, they both agree withtest results. Therefore, the theoretical formula and numerical simulation method canapproximately estimate the CTE of RFC.