Analysis For Chloride Transmission Of Cement Raw Materials Under Multi-factor Integration Effect

Chloride penetration is one of the important reasons leading to durability damage of cement-based materials.The environmental factors including temperature,flexural loading and sulphate have brought significant influence to chloride spreading in cement raw materials.So it is very important to durability of cement raw materials if we study the transmission mechanism and process for chloride under certain environmental condition and establish transmission model for related environment.In this article,chloride penetration experiment method has been established under temperature,flexural load and sulphate with natural immersion method to simulate chloride transmission process influenced by environmental factors in practical engineering.Main contents and research result have been listed as follows:(1)Through mechanics function test,the evolution pattern for flexural and compressive strength and mineral admixtures under three days,seven days and twenty-eight days standard maintenance have been summarized.(2)The Immersion test of chloride solution has been carried out to cement mortar under different temperature and cement mortar mixed with mineral admixture.Detailed analysis has been carried out to experiment result and temperature influence degree to chloride transmission and binding has been summarized.Meanwhile,the evolution pattern between chloride binding and mineral admixture has been demonstrated.(3)A loading-on device has been designed to handle loading process for ordinary cement mortar and cement mortar mixed with mineral admixture.After that,the immersion test of chloride solution has been carried out for testing module and device in order to achieve several target including(1)analyzing loading effect influence to chloride transmission and binding power(2)proposing chloride expanding mode with consideration of mineral admixture and loading effect(3)Confirming parameters in the model and introducing binding coefficient for chloride.(4)The immersion tests of chloride solution to cement mortar under different sulfate concentration and water cement ratio have been handled and the influence pattern to chloride binding capacity from sulfate and water cement ratio has been summarized.Mathematical model has been built up to assess chloride binding capability to cement raw materials from water cement ratio and sulfate concentration;Meanwhile,chloride spreading model with consideration of water cement ratio and sulfate has been established through chloride diffusion coefficient.(5)The micro-morphology and pore structure characteristics for cement raw materials under different temperature and sulfate environment have been measured with X ray diffractometer,thermal analyzer and scanning electron microscope.Therefore,evolution pattern for micro-morphology and pore structure characteristics according to mineral admixture quantity,category,water cement ratio and temperature have been obtained.The experiment results and theoretical achievements in cement raw materials function and chloride penetration fields have been enriched from certain extent and this has offered important theoretical support to solve problems in temperature,loading and anti-chloride erosion for cement raw materials under sulfate environment.