热养护方式对轨枕混凝土性能影响的研究

Experimental Study on the Influence of Thermal Curing Mode on the Performance of Sleeper Concrete

对轨枕生产涉及的静停时间和干热养护、蒸汽养护的组合养护方式进行了较为详细的试验研究,利用混凝土强度和表观吸水率进行评价。结果表明:混凝土构件成型后,静停3h,在蒸汽养护条件下,混凝土脱模强度和表观吸水率较佳,脱模后标养7d对混凝土强度发展较为有益,有助于表观吸水率的降低。在干热养护条件下,静停时间对脱模强度和吸水率影响不大,但对同条件养护至28d吸水率影响较大,静停3h为最佳。同理,脱模后的保湿养护对强度的发展较为有益,并可有效降低吸水率。采用干热养护+蒸汽养护组合的方式,前期可有效降低混凝土含水率,提高强度,后期通过蒸汽养护补充水分,可促使混凝土后期强度的发展,干热养护3h+蒸汽养护2h效果较佳,并且,较蒸汽养护5h,可降低能耗24%。

In this paper,the sleeper production involves static stop time,dry heat curing,steam curing,and two kinds of combination way of maintenance,test research are discussed in detail,using concrete strength and apparent bibulous rate were evaluated.Result surface:the demoulding strength and apparent water absorption of concrete are better under the steam curing condition after the concrete component formed and stopped for 3h.After demoulding,the standard curing for 7d is beneficial to the development of concrete strength and the reduction of apparent water absorption.Under dry hot curing condition,the static stop time has little influence on the demoulding strength and water absorption,but has a great influence on the water absorption after curing to 28d under the same condition,and the static stop time of 3h is the best.Similarly,moisture preservation after demoulding is beneficial to the development of strength and can effectively reduce water absorption.The combination of dry heat curing and steam curing can effectively reduce the moisture content and improve the strength of concrete in the early stage.In the later stage,water supplement by steam curing can promote the later strength of concrete,the effect of dry heat curing 3h+steam curing 2h is better,compared with steam curing for 5h,the energy consumption can be reduced by 24%.