文章信息/Info

Title:

Experimental Study on Self�睭ealing Performance of Crack of Green Toughness Cementitious Composities

作者:

鮑文博; 王東旭; 王懷成

沈陽工業(yè)大學(xué)建筑與土木工程學(xué)院

Author(s):

BAO Wenbo;  WANG Dongxu;  WANG Huaicheng

School of Architecture and Civil Engineering, Shenyang University of Technology

關(guān)鍵詞:

綠色延性水泥基材料（GTCC）; 尾礦砂; 聚乙烯醇（PVA）纖維; 抗壓強(qiáng)度恢復(fù)率; 自愈合

Keywords:

green toughness cementitious composites(GTCC);  tailings sand;  polyvinly alcohol(PVA) fiber;  compressive strength recovery method;  self�瞙ealing

DOI:

10.7502/j.issn.1674-3962.2019.04.10

文獻(xiàn)標(biāo)志碼:

A

摘要:

綠色延性水泥基復(fù)合材料（green toughness cementitious composities，GTCC），是借鑒高延性水泥基復(fù)合材料(engineered cementitious composites, ECC)技術(shù)開發(fā)的一款聚乙烯醇((polyvinly alcohol, PVA)纖維增強(qiáng)尾礦砂水泥基復(fù)合材料，該復(fù)合材料以大比例尾礦砂替代天然細(xì)骨料，具有經(jīng)濟(jì)、環(huán)保和延性特性。目前對于該復(fù)合材料的研究主要局限于產(chǎn)品制備、力學(xué)性能和耐久性等方面，有關(guān)GTCC裂縫自愈合性能的研究至今尚未見報(bào)道。為了探究該復(fù)合材料的自愈合性能，設(shè)計(jì)了尾礦砂替代天然砂比率為50%的3組不同水膠比的立方體試件，采用抗壓強(qiáng)度恢復(fù)率法對GTCC的自愈合性能進(jìn)行了研究，研究了損傷齡期、養(yǎng)護(hù)齡期、養(yǎng)護(hù)環(huán)境及干濕循環(huán)周期等因素對該新型材料自愈合效果的影響，揭示了綠色延性水泥基復(fù)合材料在不同條件下的自愈合規(guī)律。結(jié)果表明：該復(fù)合材料的損傷齡期越早，其自愈合效果越好；其自愈合效果隨著自愈合養(yǎng)護(hù)齡期的增加而增加，但后期增長率較早期增長率越來越弱；干濕循環(huán)養(yǎng)護(hù)環(huán)境相對其它環(huán)境，更有利于其自愈合發(fā)生；自愈合作用主要發(fā)生在21個(gè)干濕循環(huán)之前。

Abstract:

Green toughness cementitious composites(GTCC) is one kind of polyvinly�瞐lcohol(PVA) fiber�瞨einforced tailing sand engineered cementitious composites, which was developed by engineered cementitious composites(ECC) technology. The composite replaces natural fine aggregate with a large proportion of tailing sand, which has the characteristics of economy, environmental protection and ductility. At present, the research on this composite material is mainly confined to the aspects of product preparation, mechanical properties and durability. The research on the self�瞙ealing property of GTCC cracks has not been reported yet. In order to explore the self�瞙ealing properties of the composites, three groups of cube specimens containing 50% tailings sand and 50% natural sand with different water�瞓inder ratios were designed， the self�瞙ealing properties of GTCC were studied by compressive strength recovery method. Through the compressive strength experiment, the influences of damage age, self�瞙ealing age, curing condition and cycles of wet�瞕ry conditioning on the self�瞙ealing effect of the new material were discussed. The results show that the earlier the composite material is damaged, the better the self�瞙ealing effect is. The self�瞙ealing effect increases with the increase of self�瞙ealing age, but the later growth rate is weaker than the early growth rate. The wet�瞕ry conditioning is more conducive to its self�瞙ealing than other environment. Self�瞙ealing occurrs primarily before the 21st wet�瞕ry cycles.