盐冻循环作用下蒸养混凝土的性能劣化机理及损伤本构模型研究

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中图分类号：TU528 文献标志码：A

Abstract：Freezethawcyclesandsaltionerosionaremajrfactorscontributingtothedegradationoftesrvicelifeofassembledwater conveyancechannels.Toreveal theperformancedegradationmechanismofsteam-curedoncreteinsaltfreeze-thawenvironentsandto constructadamageconstitutivemodel，steam-curedconcretewasseletedastheresearchobject.Saltfreze-thawcycletestsadacro microscaleexperimental studieswerecariedout.Basedonthe Weibullrandomdisributionanddamagemechanicsprinciples，a uniaxialcompresiondamageconstitutivemodelforconcreteconsideringsaltfreeze-thawcycleswasestablished.Theresultsshowthat withtheincreaseinsaltfreze-haccles，terelativedamiclastcodulus，ompresivestrengthandelasticodulusofcocete graduallydecreasehilethepeakstrainandmasslossratecotiuetoincrease.Thecoupledfectofsaltfreee-thaccleselarges te internalporesoftheoncrete，leadingtofurtercackpropagatioandaceleratigtheoncretedamageprocess.eelasticmodulus， peakstress，andpakstrainobtainedfromtheoreticalcalculationsagreewiththeexperimentaldatavalidatingtherationalityofthe theoreticalmodel.Theestablishedtheoreticalmodelcancomprehensivelydescribetheperformancedegradationprocessofconcrete underloadafersaltfreze-thawcyles.Theresearchresultscanprovideareferencefortheengineeringconstructionofprefabricated water conveyance channels in saline freze-thaw regions.

Key words：steam-cured concrete;performance degradationmechanism;damage constitutive model;macro-micro scale

目前，渠道输水是新疆常见的浇灌方式，传统的现浇混凝土渠道普遍存在劳动强度大、效率低、施工成本高等缺点[1]，与传统现浇混凝土渠道相比，装配式混凝土渠道经工厂加工并养护后可直接通过吊车安装使用，从而减少工人的体力劳动，而且装配式混凝土渠道还具有施工效率高、节省施工成本等优势，所以装配式混凝土渠道在新疆已经被广泛应用[2]。（剩余13197字）