【摘要】：本論文主要研究了養(yǎng)護(hù)制度對(duì)含粗骨料超高性能混凝土(Ultra-high Performance Concrete with Coarse Aggregate,UHPC(CA))力學(xué)性能和高溫爆裂的影響,研究變量包括養(yǎng)護(hù)方式、熱水養(yǎng)護(hù)溫度和時(shí)長(zhǎng)、干熱養(yǎng)護(hù)溫度和時(shí)長(zhǎng)、鋼纖維。本研究首先通過(guò)實(shí)驗(yàn)確定了對(duì)提高UHPC強(qiáng)度和抗爆裂性能最有利的組合養(yǎng)護(hù)方式。在此基準(zhǔn)上改變干熱養(yǎng)護(hù)溫度水平,研究了干熱養(yǎng)護(hù)溫度對(duì)UHPC強(qiáng)度和抗爆裂性能的影響。最后研究了組合養(yǎng)護(hù)對(duì)UHPC(CA)抗壓強(qiáng)度、劈裂抗拉強(qiáng)度、斷裂能及高溫爆裂的影響。常溫力學(xué)性能試驗(yàn)結(jié)果顯示:(1)在不同熱水養(yǎng)護(hù)溫度下,熱水養(yǎng)護(hù)最佳時(shí)長(zhǎng)有所不同。當(dāng)熱水養(yǎng)護(hù)溫度為60℃和90℃時(shí),熱水養(yǎng)護(hù)最佳養(yǎng)護(hù)時(shí)長(zhǎng)分別為4 d和3d。(2)與標(biāo)準(zhǔn)養(yǎng)護(hù)相比,組合養(yǎng)護(hù)過(guò)后,UHPC的抗壓強(qiáng)度和劈裂抗拉強(qiáng)度均有大幅增加。對(duì)于素UHPC來(lái)說(shuō),組合養(yǎng)護(hù)后混凝土的斷裂能均大于標(biāo)準(zhǔn)養(yǎng)護(hù)后,但對(duì)于摻鋼纖維的UHPC來(lái)說(shuō),組合養(yǎng)護(hù)對(duì)混凝土的斷裂能帶來(lái)了不利影響。高溫爆裂試驗(yàn)結(jié)果顯示:標(biāo)準(zhǔn)養(yǎng)護(hù)下的UHPC在高溫爆裂試驗(yàn)中均發(fā)生非常嚴(yán)重的爆裂。組合養(yǎng)護(hù)可以顯著提高UHPC的高溫爆裂性能,且提高效果與熱水養(yǎng)護(hù)和干熱養(yǎng)護(hù)的溫度和時(shí)長(zhǎng)密切相關(guān),隨著熱水養(yǎng)護(hù)時(shí)長(zhǎng)增加,UHPC高溫性能越差;提高干熱養(yǎng)護(hù)溫度能在UHPC中達(dá)到消除爆裂的效果。高溫后殘余力學(xué)強(qiáng)度試驗(yàn)結(jié)果顯示:組合養(yǎng)護(hù)條件下,UHPC經(jīng)過(guò)高溫爆裂試驗(yàn)后仍然具有較高的殘余抗壓強(qiáng)度和殘余劈裂抗拉強(qiáng)度。同時(shí),摻加鋼纖維有利于提高UHPC高溫后的殘余強(qiáng)度;且與單摻鋼纖維相比,兩種鋼纖維混摻時(shí)效果更佳。本文研究表明,組合養(yǎng)護(hù)的方法可以大幅提高其基本力學(xué)性能和抗爆裂性能。熱水養(yǎng)護(hù)及干熱養(yǎng)護(hù)的溫度、時(shí)長(zhǎng)均會(huì)對(duì)UHPC強(qiáng)度產(chǎn)生一定影響。標(biāo)準(zhǔn)養(yǎng)護(hù)條件下,鋼纖維能對(duì)UHPC的高溫爆裂起到一定緩解。組合養(yǎng)護(hù)條件下,UHPC經(jīng)過(guò)高溫爆裂試驗(yàn)后仍然具有較高的殘余強(qiáng)度。
[Abstract]:In this paper, the effect of curing system on the mechanical properties and high temperature burst of ultra-high performance concrete (Ultra-high Performance Concrete with Coarse Aggregate,UHPC (CA) containing coarse aggregate is studied. The variables include curing mode, hot water curing temperature and time. Dry heat curing temperature and time, steel fiber. In this study, the most favorable combination maintenance method for improving the strength and burst resistance of UHPC was determined by experiments. The effect of dry heat curing temperature on the strength and burst resistance of UHPC was studied by changing the level of dry heat curing temperature. Finally, the effects of combined curing on the compressive strength, split tensile strength, fracture energy and high temperature burst of UHPC (CA) were studied. The results of mechanical properties test at room temperature show that: (1) the optimum time length of hot water curing is different at different hot water curing temperatures. When the curing temperature of hot water is 60 鈩，

本文編號(hào)：2484117