沸石粉水泥砂浆早期力学性能改善及机理研究  

Improvement of early mechanical properties and mechanism of zeolite powder cement mortar

作　　者：马晓宁 龙广成[1] 廖志泓 谢友均[1] 杨恺 肖其远 向宇 MA Xiaoning;LONG Guangcheng;LIAO Zhihong;XIE Youjun;YANG Kai;XIAO Qiyuan;XIANG Yu(School of Civil Engineering,Central South University,Changsha 410075,China;Changsha Project Construction Command Department of China Railway Guangzhou Bureau Group Co.,Changsha 410007,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中国铁路广州局集团有限公司长沙工程建设指挥部,湖南长沙410007

出　　处：《铁道科学与工程学报》2024年第9期3636-3646,共11页Journal of Railway Science and Engineering

基　　金：湖南省自然科学基金资助项目(2023JJ30679);公路养护技术国家工程研究中心(长沙理工大学)开放基金资助项目(kfj220106)。

摘　　要：为了降低大掺量沸石粉对早期强度的削弱作用,进一步提高沸石粉在水泥基材料中作用效率,促进其在水泥基材料中的应用,通过设计系列试验,探究交流电场直接养护(electric curing,EC)、无机系早强剂(硫酸钠、硅酸钠)及二者共同作用下沸石粉掺量对砂浆强度的影响规律,并通过水化放热和孔结构测试分析,探讨其相应机理。通过测试28 d水泥砂浆抗压强度评估直接电养护、早强剂及2种方法耦合对后期强度的影响。研究结果表明:砂浆强度随沸石粉掺量呈现出先增加而后降低的规律,掺10%沸石粉砂浆的1 d、28 d抗压强度相较于基准砂浆分别约提高了19%、8%。直接电养护和早强剂硫酸钠均能显著提高掺沸石粉水泥砂浆的早期强度,直接电养护的改善效果略低于硫酸钠;在电养护与硫酸钠共同作用下,能进一步提升较高沸石粉掺量砂浆的强度,沸石粉掺量30%时,试件1 d抗压强度最高可提高达25%。水化热结果显示,随着沸石粉掺量的增加,浆体72 h累计水化放热出现不同程度的降低,沸石粉可在一定程度上促进水化,沸石粉与硫酸钠共同作用可明显提高体系水化放热速率和放热量。掺入沸石粉对体系孔隙有一定细化作用,直接电养护的试件28 d龄期累计孔隙含量稍高于标准养护。本研究可为改善大掺量沸石粉水泥砂浆早期力学性能提供思路,对促进沸石粉在水泥混凝土中的应用具有重要意义。To reduce the weakening effect of large dosage of zeolite powder on early strength,further improve the efficiency of zeolite powder in cementitious materials and promote its application in cementitious materials.The experiments aimed to investigate the effect of zeolite powder dosing on the strength of composite mortar under two effects,which were Electric curing(EC)and early-strengthening agent(Sodium sulfate,sodium silicate).And through the hydration exotherm and pore structure test analysis,to explore its corresponding mechanism.The effects of electric curing,early-strengthening agent and the coupling of the two methods on the strength at the later stage were evaluated by testing the compressive strength of cement mortar at 28 d.The results are shown as follows.The strength of mortar increases and then decreases with the dosage of zeolite powder.Compared with the reference mortar,the 1 d and 28 d compressive strengths of mortar doped with 10%zeolite powder increases by about 19%and 8%.Both electric curing and sodium sulfate can significantly improve the early strength of zeolite powder cement mortar,but the improvement effect of direct electric curing is slightly lower than that of sodium sulfate.Under the coupling effect of electric curing and sodium sulfate,the early strength of mortar with high zeolite powder dosage is improved.The 1 d compressive strength of specimens dopes with 30%zeolite powder can be increased up to 25%.The results of hydration heat show that,with the increase of zeolite powder doping,the cumulative hydration exotherm of the slurry 72 h appeared to be reduced to different degrees,zeolite powder can promote hydration to a certain extent,zeolite powder and sodium sulfate together can significantly increase the rate of hydration exotherm of the system and the amount of exotherm.The admixture of zeolite powder has a certain refining effect on the pores of the system,and the cumulative pore content at the age of 28 d of the specimens with electric curing is slightly higher than that of stand

关 键 词：沸石粉 直接电养护 早强剂 力学性能 砂浆 

分 类 号：TU528[建筑科学—建筑技术科学] TU992.3