Design And Performance Of Cement Mortar For Connection Of Reinforced Concrete Drainage Pipeline

In the early stage of our country,there were many damages at the interface of the drainage pipeline,which seriously affected the safety of the drainage system.In addition,the demand of the urban drainage pipeline construction is increasing.The quality control of the connection at the interface of the pipeline has become a key,and the materials used in the interface are the most important.In this study,silicon powder and silane coupling agent were added to cement mortar to study the effect of both on the performance of cement mortar,so as to design a better cement mortar for pipeline interface.The main contents and conclusions of this paper are as follows:(1)Experiments were conducted on the flow properties,mechanical properties and impermeability of cement mortar and test pieces with different amounts of silica powder,and the results show that the fluidity of the cement mortar increases first and then decreases with the increase of the content of silica fume,and the appropriate content is about 4%.The compressive strength,flexural strength and water pressure of the cementmortar increase first and then decrease with the increase of the content of silica fume With the increase of silica powder content,the static water absorption of cement mortar first decreased and then increased.According to the comprehensive performance test,8% silicon powder is the best.(2)The silicon powder mortar and test pieces with different silane coupling agent dosages were tested for flow properties,mechanical properties and bonding properties,and the results show that the fluidity of silicon powder mortar increases with the increase of silane coupling agent content,the compressive strength and flexural strength decrease with the increase of silane coupling agent content,and the bond strength increases first with the increase of silane coupling agent content The trend of decreasing after rising is about 3%.(3)The tests of water absorption rate,impermeability and acid or alkali corrosion resistance of silicon powder mortar and test pieces with different silane coupling agent content were carried out.The results showed that the water absorption of silicon powder mortars decreased first and then increased with the increase of silane coupling agent content,and the appropriate content was about 4%;the water resistance value of silicon powder mortars increased first and then decreased with the increase of silane coupling agent content With the increase of silane coupling agent content,the acid corrosion resistance coefficient of silicon powder mortar increasesfirst and then decreases,the appropriate content is 3%,and the alkali corrosion resistance coefficient decreases.According to the properties of silicon powder mortar,3% is the optimum content of silane coupling agent.(4)Electron microscopy scanning analysis was carried out on mortar specimens with different silane coupling agent dosages.The results showed that: at the 3% and 4% dosages,a large number of polymer units were cross-linked with each other,and the structure was stable to form a film.Containing more hydrophobic groups with low surface tension makes the structural system denser.