摘要
为研究含再生骨料水泥基材料的收缩性能并减小收缩率,利用非接触式自收缩仪探究了高吸水性树脂SAP掺量(0.1%~0.3%)、SAP粒径(30目、60目)对超早龄期、早龄期和长龄期下含再生骨料掺量(0%、50%、100%)水泥基材料自收缩性能影响。结果表明:1)再生水泥基材料的超早期(3 d内)自收缩率可达总收缩率的53.1%~91.6%,且自收缩率的控制效果与再生骨料掺量、SAP掺量、SAP粒径密切相关;2)100%再生骨料可将超早龄期(3 d)和长期(90 d)自收缩率分别提高53%~118%、36.2%~78.5%;3)50%再生骨料掺量下,0.1%~0.3%的SAP掺量范围内可将90 d自收缩率降低32.6%~53.9%,而100%再生骨料掺量下,仅0.3%的SAP才能起到减缩效果;4)SAP目数对自收缩率的削减效果受再生骨料掺量的敏感性高;5)BP神经网络能准确预测不同龄期自收缩率与再生骨料掺量、SAP掺量、SAP粒径的关系,基于此提出了低收缩再生水泥基材料的优化设计策略。
To study the shrinkage properties of cementitious materials containing recycled aggregates and to reduce the shrinkage,the effects of high absorbent resin SAP admixture(0.1%-0.3%)and SAP particle size(30,60 mesh)on the self-shrinkage performance of cementitious materials with different recycled aggregate admixtures(0,50%,100%)at ultra-early age,early age and long age were investigated using a non-contact self-shrinkage instrument.The results showed that:1)the self-shrinkage of recycled cementitious materials in the ultra-early(within 3 d)stage could reach 53.1%~91.6%of the total shrinkage,and the control effect of self-shrinkage was closely related to the amount of recycled aggregate admixture,SAP admixture and SAP particle size;2)100%recycled aggregate could increase the self-shrinkage rate in the ultra-early(3 d)stage and long-term(90 d)stage by 53%~118%and 36.2%-78.5%,respectively;3)Under 50%recycled aggregate admixture,0.1%~0.3%SAP admixture can reduce 90d self-shrinkage rate by 32.6%~53.9%,while under 100%recycled aggregate admixture,only 0.3%SAP can reduce the shrinkage effect;4)The reduction effect of SAP mesh on self-shrinkage is highly sensitive by the amount of recycled aggregate admixture;5)BP neural network can accurately predict the relationship between self-shrinkage and recycled aggregate dosage,SAP dosage,and SAP particle size at different ages,based on which an optimized design strategy for low-shrinkage recycled cementitious materials is proposed.
作者
洪亮
仲小玲
陈芳
HONG Liang;ZHONG Xiaoling;CHEN Fang(Xinjiang Uygur Autonomous Region Bureau of Comprehensive Transportation Administration and Law Enforcement,Urumqi 830011;Xinjiang Agricultural University,Urumqi 830011;Xinjiang Transportation Construction Group Co.,Ltd.,Urumqi 830011)
出处
《公路交通技术》
2024年第2期87-96,共10页
Technology of Highway and Transport
关键词
水泥基材料
再生骨料
高吸水性树脂
自收缩
优化策略
cementitious materials
recycled aggregates
super absorbent polymer
self-shrinkage
optimization strategies
