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Early Stage Hydration Mechanism of Cellulose Ether Modified Thin Layer Cement Pastes

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Journal of Wuhan University of Technology(Materials Science) 2012年第6期27卷 1172-1176页

作者：马保国 SU Lei jian shouwei SONG Xuefeng State Key Laboratory of Silicate Building Materials Wuhan University of Technology

The early stage hydration mechanism of cellulose ether modified thin layer cement pastes was studied, using brick as the matrix. Samples of 6 h, 24 h, and 3 d and 7 d hydration time were analyzed to study the hydration law on the surface of high water-absorbing matrix. Hydration products were qualitatively and semi-quantitatively analyzed using XRD, TG-DSC-DTG, FTIR and SEM. The experimental results show that there is no enough water for 2 mm thick cement pastes to hydrate, because of rapid water absorption of matrix. Trace amounts of Ca （OH）2 was detected after three days hydration. With the prolongation of hydration time, the category and concentration of hydration products do not change. Compared with 2 mm thick cement pastes, 6 mm thick cement pastes and 10 mm thick cement pastes have lower dehydration rate and water loss. The humidity field of the cement paste show different changes within the same time. 6 mm thick cement paste and 10 mm thick cement pastes have longer time and more water to hydrate. Ca（OH）2 and ettringite were detected after 6 hours hydration and the concentrations of hydration products increased from 24 hours to 7 days.

关键词： cellulose ether thin layer cement pastes high water-absorbing matrix hydration products

碱激发垃圾焚烧底灰地聚物的制备及其水化特性研究

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硅酸盐通报 2024年第1期43卷 287-294页

作者：刘刚李心诚刘金军蹇守卫范璐璐涂亮亮武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070 武汉理工大学材料科学与工程学院武汉430070 深圳市特区建工集团有限公司深圳518000

本文采用城市垃圾焚烧底灰(BA)、偏高岭土和矿粉作为原料,NaOH和水玻璃作为碱激发剂来制备底灰地聚物,重点研究了不同碱含量、BA掺量对聚合物抗压强度及水化特性的影响。研究表明:当碱含量达7%(质量分数,下同)时,过量的钠与活性钙、活... 详细信息

本文采用城市垃圾焚烧底灰(BA)、偏高岭土和矿粉作为原料,NaOH和水玻璃作为碱激发剂来制备底灰地聚物,重点研究了不同碱含量、BA掺量对聚合物抗压强度及水化特性的影响。研究表明:当碱含量达7%(质量分数,下同)时,过量的钠与活性钙、活性硅和铝反应,从而形成大量低强度N-A-S-H,使底灰地聚物强度下降;当碱含量固定、BA掺量达到80%时,底灰地聚物的强度大幅度降低。对于底灰而言,其聚合物体系对重金属离子具有显著的固化效果。因此,采用BA制备底灰地聚物对城市固废绿色再生利用和环境保护具有重要意义。

关键词：碱激发垃圾焚烧底灰地聚物强度重金属固化

Hydration Heat Effect of Cement Pastes Modified with Hydroxypropyl Methyl Cellulose Ether and Expanded Perlite

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Journal of Wuhan University of Technology(Materials Science) 2013年第1期28卷 122-126页

作者：苏雷 MA Baoguo jian shouwei ZHAO Zhiguang LIU Min State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology

Hydration heat effect of cement pastes and mechanism of hydroxypropyl methyl cellulose ether （HPMC） and expanded perlite in cement pastes were studied by means of hydration exothermic rate, hydration heat amount, FTIR and TG-DTG. The results show that HPMC can significantly delay the hydration induction period and acceleration period of cement pastes. As mixing amount increased, hydration induction period of cement pastes enlarged and accelerated period gradually went back. At the same time, the amount of hydration heat gradually decreased. Expanded perlite had worse delay effects and less change of hydration heat amount of cement pastes than HPMC. HPMC changed the structure of C-S-H during cement hydration. The more amount of HPMC, the more obvious effect. However, EXP had little influence on the structure of C-S-H. At the same age, the content of Ca （OH）2 in cement pastes gradually decreased as the mixing amount increase of HPMC and expanded perlite, and had better delay effect than that single-doped with HPMC or expanded perlite when HPMC and expanded nerlite were both dooed in cement pastes.

关键词： hydroxypropyl methyl cellulose ether expanded perlite cement pastes hydration heat hydrationprocess

Analysis of Air Voids Evolution in Cement Pastes Admixed with Non-ionic Cellulose Ethers

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Journal of Wuhan University of Technology(Materials Science) 2018年第4期33卷 915-923页

作者：欧志华 XIAO Yi 王菁菁 MA Baoguo jianG Longmin jian shouwei School of Civil Engineering Hunan University of TechnologyZhuzhou 412007China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China

Four cellulose ethers（CEs） were compared for their effects on the pore structure of cement paste using mercury intrusion porosimetry. The experimental results show that the total pore volume and porosity of cement pastes containing the four cellulose ethers are significantly higher than that of the pure cement pastes and the total pore volume and porosity of cement pastes containing HEC（hydroxyethyl cellulose ether） or low viscosity cellulose ethers are low in four CEs. By changing the surface tension and viscosity of liquid phase and the strengthening of liquid film between air voids in cement pastes, CEs affect the formation, diameter evolution and upward movement of air voids and the pore structure of hardening cement paste. For the four CEs, the pore volume of cement pastes containing HEC or low viscosity cellulose ethers is higher with the diameter of 30-70 nm while lower with the diameter larger than 70 nm. CEs affect the pore structure of cement paste mainly through their effects on the evolvement of the small air voids into bigger ones when the pore diameter is below 70 nm and their effects on the entrainment and stabilization of air voids when the pore diameter is above 70 nm.

关键词： cellulose ethers cement pastes pore structure air voids diameter evolution

Effect of Competitive Adsorption between Sodium Tripolyphosphate and Naphthalene Superplasticizer on Fluidity of Cement Paste

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 334-340页

作者：谭洪波 MA Baoguo LI Xiangguo jian shouwei YANG Hu State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology

The adsorption amount, ξ-potential of cement particles and fluidity of cement paste were tested to research the competitive adsorption between naphthalene superplasticizer （FDN） and STPP. The experimental results showed that the presence of STPP could significantly improve the fluidity of cement paste and reduce the fluidity loss with FDN. There existed a competitive adsorption between STPP and FDN. STPP and calcium ions formed complexes; they preferentially adsorbed onto surface of cement particles and preempt adsorption points of FDN; and it reduced adsorption amount of FDN. In the absence of STPP, saturation adsorption amount of FDN was 5.93 mg/g; but when the dosage of STPP was 0.1%, it reduced to 4.3 mg/g （about 72.5%）. The adsorption amount of FDN was reduced by STPP, but ξ-potential of cement particles enhanced and fluidity of cement paste increased because of strong negative charge effect of the complexes. Adsorption of the complexes would delay Ca^2＋ into liquid and inhibit formation of active adsorption points. Then, content of FDN in liquid increased with the addition of STPP and ξ-potential of cement particles became stable. In this way, fluidity loss of cement paste reduced.

关键词： sodium tripolyphosphate naphthalene superplasticizer ξ-potential complex competitive adsorption

凹凸棒土对石膏3D打印材料基本性能和可打印性能的影响

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硅酸盐通报 2024年第5期43卷 1748-1755页

作者：汪才峰蹇守卫李宝栋黄健翔高欣马逍遥薛文浩武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

增稠剂是3D打印材料的关键组分,但常用的增稠剂以有机物为主,会降低石膏的力学性能。为此,本文选取了凹凸棒土与羟丙基甲基纤维素醚作对比,测试了凹凸棒土对石膏3D打印材料工作性能、力学性能以及实际打印性能的影响。结果表明:与羟丙... 详细信息

增稠剂是3D打印材料的关键组分,但常用的增稠剂以有机物为主,会降低石膏的力学性能。为此,本文选取了凹凸棒土与羟丙基甲基纤维素醚作对比,测试了凹凸棒土对石膏3D打印材料工作性能、力学性能以及实际打印性能的影响。结果表明:与羟丙基甲基纤维素醚相似,凹凸棒土降低了石膏3D打印材料的流动度,增加了动态屈服应力;随凹凸棒土掺量增加,材料抗折抗压强度先降低后增加,而羟丙基甲基纤维素醚组抗折、抗压强度则呈下降趋势;在实际打印中,凹凸棒土组体积稳定性和开放时间结果与羟丙基甲基纤维素醚组相似,实际打印强度高于羟丙基甲基纤维素醚组23%以上。羟丙基甲基纤维素醚通过吸水溶胀、分子缠绕来提高浆体的黏度,而凹凸棒土具有丰富的孔结构,在浆体中以氢键和范德瓦耳斯力吸附水分子和增稠石膏颗粒。

关键词：高强石膏 3D打印无机增稠剂凹凸棒土工作性能可打印性

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低硅铁尾矿制备轻质泡沫混凝土试验研究

金属矿山 2024年第4期 269-274页

作者：韩厚胜李育彪潘梦真陈坤张媛顾雲翔薛璐韬蹇守卫武汉理工大学资源与环境工程学院湖北武汉430070 矿物资源加工与环境湖北省重点实验室湖北武汉430070 硅酸盐建筑材料国家重点实验室湖北武汉430070

为解决低硅铁尾矿堆存量大、利用困难等问题,以杨家湾尾矿库内低硅铁尾矿为矿物掺和料,水泥为胶凝材料,Al粉为发泡剂,制备轻质泡沫混凝土,并考察了水泥掺量、水料比、发泡剂Al粉掺量、激发剂CaO掺量等因素对泡沫混凝土性能的影响。结果... 详细信息

为解决低硅铁尾矿堆存量大、利用困难等问题,以杨家湾尾矿库内低硅铁尾矿为矿物掺和料,水泥为胶凝材料,Al粉为发泡剂,制备轻质泡沫混凝土,并考察了水泥掺量、水料比、发泡剂Al粉掺量、激发剂CaO掺量等因素对泡沫混凝土性能的影响。结果表明:在铁尾矿掺量55%、Al粉掺量0.14%、CaO掺量5%、聚丙烯纤维掺量0.3%、稳泡剂掺量0.25%、水料比0.55的条件下,经20±1℃恒温恒湿养护28d,可制备出抗压强度1.84MPa、干密度768.61kg/m^(3)、比强度2.394×10^(-3)Nm/kg的轻质泡沫混凝土,综合性能良好,符合JG/T266—2011《泡沫混凝土》之A08干密度等级、C1强度等级要求。机理分析表明:孔隙率的过度提高会破坏制品内部的孔隙结构,对制品强度造成负面影响;铁尾矿的添加有助于混匀料浆,促进Ca(OH)2的生成,为料浆进一步创造碱性环境,促进钙矾石、C—S—H凝胶等水化产物的生成,其与铁尾矿的交织分布会支撑起孔隙结构,改善力学结构,使泡沫混凝土即使在较低密度下仍表现出较好的力学性能。

关键词：低硅铁尾矿泡沫混凝土机理 Al粉比强度

不同无机增稠剂对3D打印水泥基材料性能的影响

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硅酸盐通报 2024年第5期43卷 1642-1650页

作者：马逍遥蹇守卫李宝栋黄健翔高欣薛文浩汪才峰武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

3D打印水泥基材料的工作性能是影响其最终状态的决定性因素,现有技术多采用有机增稠剂调节其工作性能,但存在强度下降、成本较高等问题。本文选用凹凸棒土、硅藻土和钠基膨润土三种无机增稠剂,研究了在不同增稠剂掺量下3D打印水泥基材... 详细信息

3D打印水泥基材料的工作性能是影响其最终状态的决定性因素,现有技术多采用有机增稠剂调节其工作性能,但存在强度下降、成本较高等问题。本文选用凹凸棒土、硅藻土和钠基膨润土三种无机增稠剂,研究了在不同增稠剂掺量下3D打印水泥基材料的工作性能和力学性能。结果表明,3D打印水泥基材料的工作性能会随着无机增稠剂掺量的增加而改善,凹凸棒土和硅藻土最佳掺量为2.5%(质量分数),钠基膨润土最佳掺量为1.0%(质量分数),其中钠基膨润土的改善效果最好。不同无机增稠剂对3D打印水泥基材料的力学性能会产生不同的影响,高掺量(2.5%)的凹凸棒土对3D打印水泥基材料的强度无不利影响,硅藻土能增强3D打印水泥基材料的后期强度,少量钠基膨润土就能显著提高3D打印水泥基材料的整体强度。掺1.0%钠基膨润土的3D打印水泥基材料具有最优的综合性能。

关键词： 3D打印无机增稠剂硫铝酸盐水泥流变性能可堆叠性力学性能

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不同生物质炉渣对蒸压加气混凝土浆料性能与力学性能的影响

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硅酸盐通报 2024年第3期43卷 987-994页

作者：薛文浩蹇守卫李宝栋黄健翔谭洪波马逍遥汪才峰武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

在电厂利用生物质发电过程中,不同焚烧工艺产生的焚烧炉渣的成分和性质不同,这为其资源化利用带来了较大的难题。本研究以生物质炉渣、水泥、石灰为主要原料制备蒸压加气混凝土(AAC),对比研究两种主流燃烧工艺产生的炉渣对AAC制品浆料... 详细信息

在电厂利用生物质发电过程中,不同焚烧工艺产生的焚烧炉渣的成分和性质不同,这为其资源化利用带来了较大的难题。本研究以生物质炉渣、水泥、石灰为主要原料制备蒸压加气混凝土(AAC),对比研究两种主流燃烧工艺产生的炉渣对AAC制品浆料性能和力学性能的影响,并通过XRD和SEM对其水化产物及微观形貌进行过测试分析。结果表明:随着机械炉排炉渣(MGI)掺量的增加,AAC浆料的初始流动度明显下降,流动度损失增大,发气体积下降;AAC试块的比强度先增大后减小,当MGI质量分数为28%时,为兼顾AAC强度和密度的最佳掺量,抗压强度和密度分别为3.6 MPa、593.22 kg/m^(3)。循环流化床炉渣(CFBC)中大量的硬石膏和游离氧化钙会影响浆料的凝结硬化,随着CFBC掺量的增加,AAC浆料初始流动度逐渐增大,发气体积上升,AAC试块的比强度持续减小。此外,AAC中的水化产物——托贝莫来石的形态和堆积密度对制品的力学性能有着显著影响。

关键词：生物质炉渣蒸压加气混凝土托贝莫来石发气速率流动度力学性能