Characteristics And Mechanism Of Mechanical Strength Control Of Ecological Mortar With High Content Slag

To make full use of the advantages of green environmental protection and outstanding material characteristics of slag concrete(including pore fine,dense microstructure,good durability,etc.),and to further increase the dosage of slag,effectively reduce the dosage of cement,relieve concrete strength degradation caused by excessive dosage of slag,this paper adopts the silicon powder,water/cement ratio and curing temperature for the performance of the.slag concrete regulation pathway,studied the dosage of silicon powder,different water/cement ratio and curing temperature on the mechanical strength,microstructure characteristics,the influence law of hydration products,volume stability and durability of slag mortars,and set up the above variables and behavior characteristics of slag slurry,the results show that:(1)Silicon powder can effectively shorten the over-long setting time of high-slag mortar and promote its early strength development.When the silicon powder content is 5%,the compressive strength of slag mortar on 28d is increased by 15.50～16.86%,and the flexural strength on 28d is increased by 1.89～26.83%.At the same time,the addition of silicon powder can effectively reduce the total porosity of mortar,effectively prevent chloride ion erosion,the maximum decrease rate of electric flux is 92.79%,capillary water absorption reduction rate is about 12%.Considering the above properties,the optimum content of silicon powder is determined to be 5%.(2)Improving the curing temperature and reducing the water-cement ratio are also effective ways to regulate the high slag performance.When the curing temperature is 40℃ the 28d compressive strength of slag mortar is 39.03 MPa,with an increase of 30.80%.When the water-cement ratio is 0.35,the 28d compressive strength of slag mortar is 40.03MPa,with an increase of 34.15%.Improving the curing temperature and reducing the water-cement ratio can further promote the hydration reaction of high slag mortar,strengthen the internal structure of mortar,and effectively improve the durability of mortar.In this test,the optimal content of silica fume(5%),the optimal curing temperature(40℃)and the optimal water-cement ratio(0.35)were finally determined,which further improved the ecological environmental protection of slag mortar with high content and promoted its wide application.Figure 42 Table 20 References 72...