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（1 內(nèi)蒙古農(nóng)業(yè)大學(xué)水利與土木建筑工程學(xué)院，呼和浩特 010018；2內(nèi)蒙古建筑職業(yè)技術(shù)學(xué)院經(jīng)濟(jì)管理學(xué)院，呼和浩特 010070）

［摘要］為研究水泥基混凝土孔隙結(jié)構(gòu)對(duì)其抗壓強(qiáng)度的影響，通過其孔隙結(jié)構(gòu)參數(shù)預(yù)測(cè)抗壓強(qiáng)度。對(duì)C30混凝土進(jìn)行宏觀抗壓強(qiáng)度試驗(yàn)、微觀電子顯微鏡試驗(yàn)（SEM）、微觀核磁共振試驗(yàn)（NMR），研究混凝土孔隙結(jié)構(gòu)對(duì)混凝土抗壓強(qiáng)度的影響，利用灰色關(guān)聯(lián)熵分析方法建立抗壓強(qiáng)度與孔隙結(jié)構(gòu)關(guān)系的數(shù)學(xué)基礎(chǔ)模型。試驗(yàn)結(jié)果表明：隨著養(yǎng)護(hù)齡期的增長(zhǎng)，有害孔與多害孔占比逐漸減少，無(wú)害孔占比逐漸增加；混凝土的橫向弛豫時(shí)間T2譜呈現(xiàn)“大峰帶小峰”的構(gòu)造，譜面積隨養(yǎng)護(hù)齡期增長(zhǎng)而減小；對(duì)抗壓強(qiáng)度影響最大的兩種因素為束縛流體飽和度（IFS）和半徑大于10μm的孔隙占比，其灰熵關(guān)聯(lián)度分別為0.997 1和0.997 2；以抗壓強(qiáng)度與束縛流體飽和度（IFS）及半徑大于10μm的孔隙占比建立GM（1，3）模型，模型預(yù)測(cè)值與試驗(yàn)值的平均相對(duì)誤差為5.11%，并利用強(qiáng)度預(yù)測(cè)模型對(duì)多處混凝土的孔隙結(jié)構(gòu)參數(shù)進(jìn)行強(qiáng)度模擬，相對(duì)誤差最小為0.4%，最大為7.75%，表明預(yù)測(cè)模型可以作為混凝土強(qiáng)度檢測(cè)的公式依據(jù)。

［關(guān)鍵詞］水泥基混凝土；孔隙結(jié)構(gòu)；演變特征；抗壓強(qiáng)度；灰熵

中圖分類號(hào)：TU502+.6文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2020)24-0116-08

Grey relational  entropy analysis of influence of cement-based concrete pore structure evolution characteristics on strength

LI Hao1, GUO Haolong1, ZHANG Yuan2

（1 College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China; 2 School of Economic Management, Inner Mongolia Technical College of Construction, Hohhot 010070, China）

Abstract:In order to study the influence of the pore structure of cement-based concrete on its compressive strength, the compressive strength was predicted through its pore structure parameters. Macroscopic compressive strength test, scanning electron microscope test (SEM) and microscopic nuclear magnetic resonance test (NMR) were conducted of C30 concrete to study the influence of concrete pore structure on concrete compressive strength, and the compressive strength and the grey relational entropy analysis method was used to establish the mathematical basic model of the relationship between compressive strength and pore structure. The test results show that with the increase of the curing age, the proportion of harmful holes gradually decreases, and the proportion of harmless holes gradually increases; the transverse relaxation time T2 graph of concrete shows a structure of “large peaks with small peaks”, and the spectrum area  decreases with the increase of the curing age; the two factors that have the greatest impact on the compressive strength are the bound fluid saturation (IFS) and the ratio of pores with a diameter greater than 10μm, and the gray entropy correlation is 0.997 1 and 0.997 2 respectively. The GM(1,3) model was established based on the compressive strength and the infinite fluid saturation (IFS) and the ratio of pores with a diameter greater than 10μm. The average relative error between the predicted value of the model and the experimental value was 5.11%, and the strength prediction model was used to simulate the strength of the pore structure parameters of the concrete. The minimum relative error was 0.4% and the maximum was 7.75%, indicating that the prediction model can be used as a formula basis for concrete strength testing.

Keywords:cement-based concrete; pore structure; evolution characteristic; compressive strength; gray entropy

*內(nèi)蒙古教育廳重點(diǎn)項(xiàng)目（NJZZ18044），內(nèi)蒙古農(nóng)業(yè)大學(xué)博士啟動(dòng)費(fèi)（RZ1900002013）。

作者簡(jiǎn)介：李昊，博士，副教授，Email：hao.li@imau.edu.cn。