路用泡沫混凝土耐久性研究

Study on durability of foamed concrete for road

分别对路用泡沫混凝土进行循环荷载、冻融循环、海水侵蚀和大气暴露等试验,分析试验前后试件无侧限抗压强度的变化规律,以评价其耐久性。结果表明:循环荷载作用次数、加载幅值和加载均值增加及海水浸泡时间延长时路用泡沫混凝土的耐久性逐渐下降;冻融次数增加时,耐久性则先提高后下降,但荷载和冻融耦合作用时,试件耐久性下降速率明显高于二者单一作用;大气暴露时则是随暴露时间的延长,耐久性先提高后下降,最后基本不变,且试件最终稳定的无侧限抗压强度高于暴露初期强度。为提高路用泡沫混凝土耐久性,建议施工中严格控制其上路面结构的平整度,并加强其28d后的养护,且对于冻融或海水侵蚀地区应采取措施进行防治。

In order to master the durability of road foam concrete,the cyclic loading,freeze-thaw cycling,seawater erosion and atmospheric exposure tests of road foam concrete were carried out,respectively. Furthermore,the change law of unconfined compressive strength before and after test is analyzed for evaluate its durability. The results show with the increase of cyclic loading times,loading amplitude,loading mean,seawater immersion time,the durability of road foam concrete gradually decreases,and with the increase of freeze-thaw cycling times,the durability becoming firstly increases and then decreases. However,when the load is coupled with the freeze-thaw,the rate of durability degradation of the specimen is obviously higher than that the single action of both. At atmospheric exposure,the durability becoming firstly increases and then decreases with the extension of exposure time,and finally remains unchanged,and the unconfined compressive strength of the specimen of finally stable is higher than the initial intensity of exposure. In order to improve the durability of road foam concrete,it is recommended to strictly control the roughness of the pavement structure during construction,and strengthen its maintenance after 28 days. In addition,the measures should be taken for prevention and control in areas with freeze-thaw or seawater erosion.