About the author:

1. China Construction Western Group Fourth （Guangdong） Co., Ltd.,Guangzhou, Guangdong 511400, China;2. China Construction Environmental Protection Building Materials Technology（Guangzhou） Co., Ltd.,Guangzhou, Guangdong 510440, China

Abstract:

To address the performance degradation of self,compacting concrete caused by the high waterabsorption and low strength of recycled aggregates, a composite pretreatment method combining pre,wetting and slurry coating modification was proposed. Comparative analysis of immersion, spraying, andhigh,pressure water,air methods identified spraying as the most efficient technique. And combined withthe fly ash,slag composite slurry, the recycled aggregates are encapsulated and strengthened.Experimental results demonstrate that this approach significantly enhances aggregate density andinterfacial properties. At a 30% replacement ratio, the pretreatment group exhibited reduced slump lossin recycled aggregate self,compacting concrete, meeting the SF1 requirements for self,compactingconcrete,while achieving 28,day compressive strength comparable to the natural aggregate referencegroup. At a 50% replacement ratio, the compressive strength loss remained controllable, and the splittingtensile strength showed marked improvement compared to the untreated group. These research resultsindicate that the pre,wetting combined with slurry coating method effectively enhances the overallperformance of recycled aggregate self,compacting concrete.