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祁義卿，錢文勛，白  銀，張  豐，葛龍甄

（南京水利科學研究院 水文水資源與水利工程科學國家重點實驗室，江蘇 南京  210029）

 

摘  要：為了研究混凝土中粗細骨料搭配比例對堿活性粗骨料堿-硅酸反應（ASR）的影響，根據(jù)工程中混凝土常見的粗細骨料比例設計了四種混合骨料比例，使用與粗骨料同源的細骨料替代粗骨料，采用砂漿棒快速法（AMBT）對四種不同比例混合骨料的堿活性進行評價；探究單摻25%粉煤灰、復摻25%粉煤灰和5%硅灰對混合骨料堿-硅酸反應的抑制效果，并對反應產(chǎn)物進行XRD分析。結果表明：四種不同比例的混合骨料仍具有潛在堿活性且不存在明顯的“最劣比”現(xiàn)象；砂漿棒試件中摻加粉煤灰、粉煤灰與硅灰后，堿活性骨料比例較低的混合骨料所受到的ASR膨脹抑制效果更明顯；粉煤灰與硅灰主要通過減少水泥水化產(chǎn)物中的CH，增加C-S-H以及改性C-S-H以增強其結合堿離子的能力來減弱ASR。

關鍵詞：堿-硅反應; 堿活性抑制; 砂漿棒快速法; 粉煤灰; 硅灰

中圖分類號：TU411  

文獻標志碼：A   

文章編號：1005-8249（2024）02-0001-06

DOI：10.19860/j.cnki.issn1005-8249.2024.02.001

 

 

QI Yiqing , QIAN Wenxun , BAI Yin , ZHANG Feng , GE Longzhen

(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China)

 

Abstract: In order to study the effect of coarse and fine aggregate matching ratios in concrete on the alkali-active coarse aggregate alkali-silicate reaction (ASR), four kinds of mixed aggregate ratios are designed according to the common coarse and fine aggregate ratios in engineering, and the alkali activity of the four kinds of mixed aggregates with different ratios was evaluated by Accelerated Mortar Bar Test (AMBT). The inhibition effects of 25% fly ash alone, 25% fly ash and 5% silica fume on the ASR of mixed aggregates are investigated, and the reaction products of the specimens are analyzed by XRD. The results show that the four different ratios of mixed aggregates still have alkali reactivity, and there is no obvious "pessimum" phenomenon. The inhibition of ASR expansion is more pronounced for mixed aggregates with lower proportions of alkali-active aggregates after the addition of fly ash and fly ash with silica fume in mortar bar specimens. Fly ash and silica fume inhibit ASR mainly by reducing CH, increasing C-S-H and modifying C-S-H to enhance its ability to bind alkali ions in cement hydration products.

Keywords: alkali-silica reaction; alkali-reactivity inhibition; accelerated mortar bar test; fly ash; silica fume

基金項目：國家重點研發(fā)計劃（2020YFC1511902）。

作者簡介：祁義卿（1999—），男，碩士研究生，主要研究方向：水工新材料及混凝土耐久性的研究。

通信作者：白銀（1999—），男，博士，教授級高級工程師，主要研究方向：水工新材料及混凝土耐久性。

收稿日期：2023-12-10