HPMC对水泥稳定全深式冷再生材料的性能影响研究

Effects of Hydroxypropyl Methyl Cellulose Ether on the Full-Deep Cold Regenerated Mixture Stabilized with Cement

针对水泥稳定全深式冷再生混合料的泌水、施工操作时间短、黏结力不足等诸多问题,通过在水泥胶砂试件中添加羟丙基甲基纤维素醚(HPMC),研究HPMC对水泥胶砂试件抗折及抗压强度的影响;进而探讨在再生混合料中掺入HPMC的可行性,重点研究了不同掺量的HPMC对水泥稳定全深式冷再生材料的性能影响。研究发现:HPMC由于引气作用会降低水泥水化后水泥胶砂试件的抗折及抗压强度;水泥在HPMC溶于水后的分散液中进行水化,与水泥先水化再掺入HPMC相比,水泥胶砂试件抗折及抗压强度有所增大。掺入HPMC,对水泥稳定全深式冷再生材料的无侧限抗压强度有削弱作用;再生混合料具有一定黏聚性能不易离析,且在常温及高温下保水性能较好,基本无泌水现象。

Aiming at the problem of bleeding,short construction operation time and insufficient cohesive force of cement stabilized full-deep cold regenerated mixtures,the effect of hydroxypropyl methyl cellulose ether (HPMC) on flexural and compressive strength of cement mortar specimens was studied by adding HPMC to cement sand specimens.The feasibility of adding HPMC into the regenerated mixtures was discussed,and the effects of different HPMC content on the properties of cement stabilized deep cold regenerated mixtures were studied.It is found that HPMC reduces the flexural and compressive strength of cement sand specimens due to air entrainment.Cement hydration in HPMC solution increases the flexural and compressive strength of cement sand specimens compared with cement hydration before HPMC is added.The addition of HPMC reduces the unconfined compressive strength of cement stabilized full-deep cold recycled regenerated specimens.The regenerated mixture has a certain cohesive property and is not easy to segregate,and has good water retention at room temperature and high temperature,basically without bleeding phenomenon.