再生水稳铣刨料干缩性能影响因素及敏感性分析

Factors Affecting the Drying Shrinkage Performance of Recycled Water Stabilized Milling Materials and Sensitivity Analysis

为研究不同因素对再生水稳铣刨料干缩性能的影响,推进铣刨料在水稳基层的应用,以河北省石太高速铣刨料为原材料,分别制备铣刨料掺量W=0%、43%、89%,水泥掺量w=4%、5%、6%,尺寸为25 mm×25 mm×280 mm的长方体试件,采用比长仪与天平分别测量不同养生时间试件的干缩量及质量变化,研究不同铣刨料掺量W、水泥掺量w以及养生时间T对试件干缩性能的影响规律,并通过正交试验法与双因素方差分析法,分析不同因素对试件累积失水率ω与累积干缩应变ε影响的敏感性。结果表明:1)各组试件随着T的增长,ω逐渐增大,A组ω最大约为7.4%;2)铣刨料掺量越大,试件的ω越小;3)养生时间T为5 d时,A组试件ω是C组试件的1.64倍;4)适当掺加部分RAP料可显著降低试件的干缩应变,提高试件的抗裂性能;5)铣刨料掺量能显著影响试件的干缩性能,当T为5 d、W由0%增加至43%时,试件干缩应变ε由362.515×10^(-6)降低至289.286×10^(-6),降低了20.20%;6)影响试件失水率ω的主要因素为铣刨料掺量W以及养生时间T;7)水泥掺量w是影响再生水稳试件干缩应变ε的主要因素,对于试件的累积干缩应变,水泥掺量的F值为18.828,是铣刨料掺量的F值的4.36倍,水泥掺量起主导作用,2种因素的交互作用对试件干缩性能无影响。

For the development of milling material in water stabilized base,this paper studies the influence of different factors on the dry shrinkage of recycled water stabilized milling material.The raw material of Hebei Shitai high-speed milling material was used to prepare cuboid specimens with the size of 25×25×280mm with the milling material content W=0%,43%and 89%and the cement content w=4%,5%and 6%,respectively.Length comparator and balance were used to measure the dry shrinkage and mass change of the specimen.The effects of different milling material content W,cement content w and curing time T on the dry shrinkage performance of the specimens were studied.In addition,the sensitivity of different factors on the cumulative water loss rateωand cumulative dry shrinkage strainεof specimens was analyzed by orthogonal experiment and two-factor analysis of variance.The results show that:1)Theωof each group increases gradually with the increase of T,and theωof group A is about 7.4%at most;2)The larger the amount of milling material,the smaller theωof the specimen;3)When the health preservation time T is 5 d,theωof group A is 1.64 times that of group C;4)The application of RAP material can significantly reduce the dry shrinkage strain of the specimen and improve the cracking resistance of the specimen;5)The amount of milling material can significantly affect the dry shrinkage performance of the specimen.When T is 5d and W increases from 0 to 43%,the dry shrinkage strainεdecreases from 362.515×10^(-6) to 289.286×10^(-6),decreasing by 20.20%;6)The main factors affecting the water loss rate of the specimen are the milling material content W and the curing time T;7)Cement content w is the main factor affecting dry shrinkage strainεof regenerated water stable specimens.For the cumulative dry shrinkage strain of the specimen,the F value of cement content is 18.828,which is 4.36 times that of milling material content,and the cement content plays a leading role.The interaction of the two factors has no effect on the dry shrinkage performance of the specimen.