减缩增强剂应用于钢渣路面基层材料的试验研究

Experimental Study on Application of Shrinkage-reducing and Reinforcing Agent in Steel Slag as Pavement Base Material

为解决细料类精炼钢渣路面基层材料收缩开裂问题,以广西北海钢渣为研究对象,通过研究减缩增强剂各组分单掺、复掺对钢渣路面基层材料强度影响规律,研发水泥稳定钢渣路面基层材料专用减缩增强剂,提高基层强度,抑制收缩,验证其路用性能,利用电镜扫描通过路面基层材料微观结构探究减缩增强剂作用机理。试验结果表明:水泥稳定钢渣混合料中水泥的最佳掺量为8%;减缩增强剂复掺的配合比(质量比)为脱硫石膏∶早强剂∶早期膨胀剂∶MgO∶硅灰∶NaOH=17∶14.5∶17∶8.5∶14.5∶28.5,且最佳掺量为3%;减缩增强剂掺量3%的抗压强度为6.19 MPa,弯拉强度为2.13 MPa,劈裂强度0.93 MPa,均满足规范要求;通过C_(1)组(掺8%水泥并掺入3%减缩增强剂)与D组(只掺8%水泥)对比分析干缩性与温缩性,可见减缩增强剂的掺入能够有效地抑制水泥稳定钢渣基层的温缩量和干缩量。

In a bid to tackle the problems of shrinkage and cracking of refined steel slag pavement base material,steel slag in Guangxi Beihai was taken as the research object.By studying the influence law of single and compound mixing of each component of shrinkage-reducing and and reinforcing agent on the strength of steel slag as pavement base material,a special shrinkage-reducing and reinforcing agent for cement stabilized steel slag pavement base material was developed to improve the base strength,inhibit shrinkage and verify its road performance.Meanwhile,the action mechanism of shrinkage-reducing and reinforcing agent was explored through the microstructure of pavement base material by scanning electron microscope(SEM).The test results show that the best amount of cement additives in cement stabilized steel slag mixture is 8%;The mix proportion of shrinkage-reducing and reinforcing agent is desulfurized gypsum∶early strength agent∶early expansion agent∶MgO∶silica fume∶NaOH=17∶14.5∶17∶8.5∶14.5∶28.5,with the optimum added quantity of 3%;The compressive strength,flexural tensile strength and splitting strength of 3%shrinkage-reducing and reinforcing agent are 6.19 MPa,2.13 MPa and 0.93 MPa,which all meet the specification requirements.Through the comparative analysis of dry shrinkage and temperature shrinkage between group C_(1)(mixed with 8%cement and 3%shrinkage-reducing and reinforcing agent)and group D(only mixed with 8%cement),it is observed that the can effectively inhibit the temperature shrinkage and dry shrinkage of cement stabilized steel slag base can be inhibited effectively with the addition of shrinkage-reducing and reinforcing agent.