工业固废磷石膏路面基层材料路用性能研究

Pavement Performance of Industrial Solid Waste Phosphogypsum Pavement Base Material

为促进磷石膏在公路工程中的规模化利用,本文通过基础力学试验、泡水膨胀试验、收缩试验、冻融循环试验、延迟成型试验以及低温自然养生试验对磷石膏路面基层材料的综合路用性能进行了系统化评估。结果表明:磷石膏路面基层材料的力学性能与普通水泥稳定碎石性能相当;磷石膏路面基层材料的28 d浸水累计膨胀率仅为0.086%,具有良好的浸水稳定性;干缩系数为116.64με/%,温缩系数为5.15με/℃,冻融循环抗压强度比为81.13%,抗收缩性能和抗冻性能显著;试件的成型时间延迟和低温养生均对混合料强度产生不利影响,延迟4 h后强度下降了24%,5℃养生条件下强度下降了33%。

In order to promote the large-scale utilization of phosphogypsum in highway engineering,the comprehensive road performance of phosphogypsum pavement base material was evaluated by typical mechanical test,bubble swelling test,shrinkage test,freeze-thaw cycle test,delayed formation test and low temperature natural curing test.The results show that the mechanical properties of phosphogypsum pavement base material are comparable to those of ordinary cement stabilized crushed stone.The 28 d cumulative expansion rate is only 0.086%,indicating good water stability.The dry shrinkage coefficient is 116.64με/%,the temperature shrinkage coefficient is 5.15με/℃,and the compressive strength ratio after freeze-thaw cycles is 81.13%,demonstrating significant shrinkage resistance and frost resistance.Both the delayed formation time and low-temperature curing have adverse effects on the strength of mixture,with a 24%strength decrease after 4 h delay and 33%strength decrease under 5℃curing condition.