文章信息/Info

Title:

Evolution Rule of Pore Structure and Thermal Performance of Foam Concrete under Accelerated Weathering Tests

文章編號(hào):

16743962(2019)12119906

作者:

丁楊1; 董晶亮2 ; 王中平3 ; 黃神恩3

(1. 浙江大學(xué)建筑工程學(xué)院，杭州 310058）
(2. 華東交通大學(xué)土木建筑學(xué)院，南昌 330013)
(3. 同濟(jì)大學(xué)材料科學(xué)與工程學(xué)院，上海 201804）

Author(s):

Ding Yang1; 2 ;  Dong Jingliang2*;  Wang Zhongping3;  Huang Shenen3

(1.School of Architecture Engineering, Zhejiang University, Hangzhou 310058, China)
(2.School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330013, China)
(3.School of Materials Science and Engineering, Tongji University, Shanghai 201804, China)

關(guān)鍵詞:

泡沫混凝土; 耐候性試驗(yàn); 孔結(jié)構(gòu); 熱工性能

Keywords:

foamed concrete;  weathering test;  pore structure;  thermal conductivity

分類號(hào):

TQ02；TU528.2

DOI:

10.7502/j.issn.16743962.201809006

文獻(xiàn)標(biāo)志碼:

A

摘要:

為明確泡沫混凝土現(xiàn)澆屋面保溫系統(tǒng)耐候性能的影響因素，對(duì)泡沫混凝土分別展開了濕熱循環(huán)、干濕循環(huán)、高低溫循環(huán)、凍融循環(huán)和多場(chǎng)耦合循環(huán)5種耐候性試驗(yàn)，通過(guò)分析泡沫混凝土孔結(jié)構(gòu)、體積吸水率和導(dǎo)熱系數(shù)變化率的演變規(guī)律揭示其耐候性能。試驗(yàn)結(jié)果表明：經(jīng)過(guò)112次濕熱循環(huán)試驗(yàn)后，泡沫混凝土的體積吸水率僅增長(zhǎng)了1.77%，導(dǎo)熱系數(shù)降低了6%；經(jīng)過(guò)112次干濕循環(huán)試驗(yàn)，泡沫混凝土的體積吸水率由20.64%增長(zhǎng)到25.63%，導(dǎo)熱系數(shù)由0.0724增長(zhǎng)到0.0836 W/(m·K)，漲幅15.47%；經(jīng)過(guò)112次高低溫循環(huán)試驗(yàn)，泡沫混凝土的體積吸水率由21.13%增長(zhǎng)到25.14%，導(dǎo)熱系數(shù)增大了6..68%；經(jīng)過(guò)112次凍融循環(huán)試驗(yàn)，泡沫混凝土體積吸水率由23.97%增長(zhǎng)到29.38%，導(dǎo)熱系數(shù)由0.0789上升至0.0980 W/(m·K)，增長(zhǎng)了24.21%；而經(jīng)過(guò)112次多場(chǎng)耦合試驗(yàn)，泡沫混凝土的體積吸水率由14.12%增長(zhǎng)到16.88%，導(dǎo)熱系數(shù)從0.0720增長(zhǎng)到0.0850 W/(m·K)，增幅18.06%。經(jīng)過(guò)干濕循環(huán)、高低溫循環(huán)、凍融循環(huán)和多場(chǎng)耦合循環(huán)4種耐候性試驗(yàn)后，泡沫混凝土中的泡孔破裂倒塌嚴(yán)重，板材開裂潰散，導(dǎo)致其保溫隔熱性能下降、體積吸水率升高。而泡沫混凝土具有很好的耐濕熱老化性能，經(jīng)過(guò)濕熱循環(huán)試驗(yàn)后，其孔結(jié)構(gòu)、體積吸水率和導(dǎo)熱系數(shù)均沒有發(fā)生顯著變化。

Abstract:

In order to understand the affect factors of weathering resistance of foam concrete cast-in-place roof insulation system, five accelerated weathering tests of foam concrete were carried out, including humid-heat cycle, dry-wet cycle, high-low temperature cycle, freeze-thaw cycle and multi-field coupling cycle. By analyzing the evolution rule of its pore structure, volume water absorption and thermal conductivity, the weathering resistance of foam concrete was revealed. The results show that the volume water absorption of foam concrete increases only 1.77% and its thermal conductivity decreases by 6% after 112 humid-heat cycles. After 112 dry-wet cycles, the volume water absorption of foam concrete increases from 20.64% to 25.63%, and its thermal conductivity increases from 0.0724 to 0.0836 W/(m·K), which has increased by 15.47%. After 112 high-low temperature cycles, the volume water absorption of foam concrete increases from 21.13% to 25��14%, and its thermal conductivity has increased by 6.68%. After 112 freeze-thaw cycles, the volume water absorption of foam concrete increases from 23.97% to 29.38%. Meanwhile, its thermal conductivity increases from 0.0789 to 0.0980 W/(m·K), which has increased by 24.21%. After 112 multi-field coupling cycles, the volume water absorption of foam concrete increases from 14.12% to 16.88%. Its thermal conductivity has increased by 18.06%, which increases from 0.0720 to 0.0850 W/(m·K). Through four kinds of accelerated weathering tests, which are dry-wet cycle, high-low temperature cycle, freeze-thaw cycle and multi-field coupling cycle, the pore structures in foam concrete has broken and collapsed seriously. Furthermore, the foam concrete sheet has cracked and collapsed. Therefore, the thermal insulation performance of foam concrete decreases and its volume water absorption increases. The foam concrete shows good performance in humid�瞙eat cycle test. During this process, the pore structure, volume water absorption and thermal conductivity of foam concrete have no significant variation.