Research Of Effects Of Surface Modified Of Aggregate On Performance Of Concrete

Concrete as the most common building materials, has been widely applied in all kinds ofbuildings. And concrete aggregate about80%of the volume of the mortar. So, theperformance of aggregate, especially the surface in contact with cement paste, plays a crucialrole in penetrability, corrosion stability, durability and globality. In this paper, we use calciumacrylate, silica sol and silane coupling agent as modifier to investigate the change ofperformance of concrete and action mechanism. Explore the impact of different modificationprocess on the properties of concrete, to seek the best technology, and do performance testingand structural characterization of modified concrete.The results showed: after aggregate modified by calcium acrylate, mechanical propertiesof concrete mortar are obviously improved. With the amount of calcium acrylate changesfrom0.9g to9g, its intensity first increases and then decreases gradually. By means of porestructure analysis, we found that the total porosity in the interface region of modified concretedeclines, and reduce the proportion of harmful holes and optimize the pore distribution. Thecorrosion resistance coefficient of concrete showed an increase with increasing amount ofcalcium acrylate and the optimal corrosion resistance coefficient is1.208. The SEM and EDSanalysis showed that interface structure and element distribution have been noticeablyimproved. And mechanical properties of concrete are significantly improved. Theexperimental results of porous concrete are in agreement with the concrete mortar results. Theresults indicate when the quantity of calcium acrylate additive is2.25%, osmotic coefficientimproved greatly.After aggregate modified by silane coupling agent, mechanical properties of concretemortar are obviously improved. The impact of silane coupling agent on the flexural strength isconsistent with their impact on the compression strength of concrete mortar. And with theamount of silane coupling agent increases from0.1125g to1.125g, its strength increases firstand then decreases. When the quantity of silane coupling agent is0.675g，The modifiedconcrete has best mechanical properties with flexural strength and compression strengthincreased by18.7%and18.1%of7days’ hydration and18.8%å'Œ19.8%of28days’ hydration.After aggregate modified with calcium acrylate and silane coupling agent, mechanicalproperties of concrete mortar are obviously improved. When the content of calcium acrylate is2.25g and silane coupling agent is0.675g, the compression strength increased by15.2%of7-days and the compression strength increased by24.5%of28-days. The modified concretehas better corrosion coefficient than the control samples. The corrosion coefficient increasedfrom1.115and1.021when singlely added with calcium acrylate and silane coupling agent to1.141when mixed with calcium acrylate and silane coupling agent.