Construction and Building Materials最新文献_第10页

Effect of CAC addition and pre-drying on the mechanical property of carbonated C2S(γ) mortar

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-23 DOI: 10.1016/j.conbuildmat.2024.139293

Kaiwei Ye , Gongpu Huang , Yaning Zhao , Qiqi Hou , Jiongming Chen , Jiajia Tian , Guotian Ye , Yuandong Mu

{"title":"Effect of CAC addition and pre-drying on the mechanical property of carbonated C2S(γ) mortar","authors":"Kaiwei Ye , Gongpu Huang , Yaning Zhao , Qiqi Hou , Jiongming Chen , Jiajia Tian , Guotian Ye , Yuandong Mu","doi":"10.1016/j.conbuildmat.2024.139293","DOIUrl":"10.1016/j.conbuildmat.2024.139293","url":null,"abstract":"<div><div>Employing calcium silicate minerals with low calcium-to-silicate ratios, such as CS, C<sub>3</sub>S<sub>2</sub>, and C<sub>2</sub>S(γ), in the preparation of carbonatable calcium silicate cement (CCSC) presents a significant advantage in reducing carbon dioxide emissions. However, the current approach of forming CCSC mainly through mold pressing methods limits its application. The preparation of castable CCSC encounters two main challenges: low hydration activity hampers the attainment of adequate demolding strength, and a high water-to-cement ratio blocks CO<sub>2</sub> transmission pathways, resulting in a low carbonation degree. To address these issues, this study proposes incorporating a small amount of calcium aluminate cement (CAC) into the C<sub>2</sub>S(γ) mortar to rapidly provide demolding strength. Subsequently, a pre-drying treatment is applied to remove a portion of free water and form pore channels, facilitating subsequent accelerated carbonation. The results showed that the addition of 15 wt% CAC enabled the C<sub>2</sub>S(γ) mortar to achieve a compressive strength greater than 2 MPa after 24 h of curing. A pre-drying time of 1 h was found to be conducive to enhancing strength during the subsequent carbonation curing process. During carbonation curing, the compressive strength of the CAC-C<sub>2</sub>S(γ) mortar increased rapidly, reaching 48.95 MPa and 50.87 MPa after 12 and 24 h of carbonation curing, respectively. The hydration products of CAC did not participate in the carbonation reaction but interconnected with the carbonation products, jointly contributing to the strength of the CAC-C<sub>2</sub>S(γ) mortar.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139293"},"PeriodicalIF":7.4,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Autoradiographic imaging of the spatial distribution of Cl-36 in concrete

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-23 DOI: 10.1016/j.conbuildmat.2024.139279

Juuso Sammaljärvi , Xiaodong Li , Stéphane Gaboreau , Stéphanie Betelu , Jérôme Donnard , Paul Sardini , Marja Siitari-Kauppi , Pierre Henocq

{"title":"Autoradiographic imaging of the spatial distribution of Cl-36 in concrete","authors":"Juuso Sammaljärvi , Xiaodong Li , Stéphane Gaboreau , Stéphanie Betelu , Jérôme Donnard , Paul Sardini , Marja Siitari-Kauppi , Pierre Henocq","doi":"10.1016/j.conbuildmat.2024.139279","DOIUrl":"10.1016/j.conbuildmat.2024.139279","url":null,"abstract":"<div><div>In this study, the transport properties of tritiated water (HTO) and Cl-36 in two different concretes were investigated. The spatial distribution of porosity and radionuclide retention within the studied materials were studied via C-14-Polymethylmethacrylate (C-14-PMMA) autoradiography and Cl-36 autoradiography, respectively. Diffusion experiments and modelling methods were used to calculate the effective diffusion coefficients and distribution coefficients of the tracers. The diffusivities of HTO and Cl-36 were considerably lower in mixed cement (CEMV)-based concrete than in Portland cement (CEMI)-based concrete. Autoradiography-based Cl-36 post-mortem examination revealed important distinctions explaining the diffusion behaviour between the two concrete materials. While there was considerable retention in both, in CEMV-based concrete, the diffusion was considerably slower than in CEMI-based concrete. Overall, the post-mortem autoradiographic imaging was successful, and a similar approach is probably applicable to other radionuclides.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139279"},"PeriodicalIF":7.4,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical behavior of half-grouted sleeve connection under the coupling of sulfate erosion and dry-wet cycles

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-23 DOI: 10.1016/j.conbuildmat.2024.139281

Tongxing Wang , Jianian Wen , Menghan Hu , Qiang Han

{"title":"Mechanical behavior of half-grouted sleeve connection under the coupling of sulfate erosion and dry-wet cycles","authors":"Tongxing Wang , Jianian Wen , Menghan Hu , Qiang Han","doi":"10.1016/j.conbuildmat.2024.139281","DOIUrl":"10.1016/j.conbuildmat.2024.139281","url":null,"abstract":"<div><div>The half-grouted sleeve connection (HGSC) is commonly used in precast concrete (PC) structures due to its convenient fabrication method, however, the long-term mechanical properties of the HGSC in corrosive environments remain unclear. Therefore, the mechanical behavior of HGSC under the coupling of sulfate erosion and dry-wet cycles (DWCs) is investigated in this paper. A total of 24 specimens with 4d and 8d embedded lengths were designed and subjected to sulfate erosion with different DWCs. The failure modes and mechanical properties of HGSCs with different embedded lengths and DWCs were comparatively analyzed. Following this, a modified bond-slip model considering sulfate erosion was proposed and validated against the measured data. The test results indicated that the failure modes of HGSCs with 4d and 8d embedded lengths were rebar fracture and slip failure, respectively. As the number of sulfate erosions increased, the performance indicators of HGSCs gradually decreased. After 180 dry-wet cycles (DWCs), the average deformation and average slip under peak load for HGSCs with an embedded length of 8d decreased by 36.6 % and 37.7 %, respectively. In contrast, for HGSCs with an embedded length of 4d, the corresponding values increased by 3.0 % and 40.1 %, respectively. The predicted bond-slip model of HGSC considering sulfate erosion agreed well with the experimental results, and it can be useful in the life-cycle modeling of the PC structures with HGSCs.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139281"},"PeriodicalIF":7.4,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of energy saving, economy and carbon emissions of melamine foam supported SiO2 aerogel in hotel buildings across various climates

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-23 DOI: 10.1016/j.conbuildmat.2024.139263

Yapeng Wang , Zhaofeng Chen , Lixia Yang , Chengqian Bian , Ting Xu , Haisheng Wu , Jianxun Zhang , Lihua He

{"title":"Evaluation of energy saving, economy and carbon emissions of melamine foam supported SiO2 aerogel in hotel buildings across various climates","authors":"Yapeng Wang , Zhaofeng Chen , Lixia Yang , Chengqian Bian , Ting Xu , Haisheng Wu , Jianxun Zhang , Lihua He","doi":"10.1016/j.conbuildmat.2024.139263","DOIUrl":"10.1016/j.conbuildmat.2024.139263","url":null,"abstract":"<div><div>The purpose of this study is to complement the advantages of SiO<sub>2</sub> aerogel with melamine foam (MF) and prepare high-performance building insulation MF/SiO<sub>2</sub> aerogel composite. The potential of reducing energy consumption, operating costs, and carbon emissions in the construction field is explored through Energy-plus building simulation software. The experimental results showed that the prepared MF/SiO<sub>2</sub> aerogel had low density (0.089 g/cm<sup>3</sup>) and excellent hydrophobic properties (water contact angle of 136°). At the same time, SiO<sub>2</sub> aerogel was uniformly distributed in the pores of MF, giving MF/SiO<sub>2</sub> aerogel excellent compressive resistance, thermal shielding performance, and flame retardancy. The simulation results of Energy Plus building simulation software in three different climatic regions (Mohe City, Taiyuan City, and Qionghai City) showed that compared to two traditional building insulation materials (extruded polystyrene board and rock wool board), using MF/SiO<sub>2</sub> aerogel as an exterior wall insulation system can effectively save operating costs and significantly reduce electricity energy consumption and carbon emissions. The simulation data indicated that this energy-saving effect was most pronounced in Mohe City located in a cold temperate climate zone; therefore, the promotion application of MF/SiO<sub>2</sub> aerogel as an exterior wall insulation material should mainly focus on cold temperate regions.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139263"},"PeriodicalIF":7.4,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Calcium nitrate as a modifier agent for metakaolin-based geopolymer mortar

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139199

Alaa M. Rashad , Ghada M.F. Essa , W.M. Morsi , E.A. Fahmy

{"title":"Calcium nitrate as a modifier agent for metakaolin-based geopolymer mortar","authors":"Alaa M. Rashad , Ghada M.F. Essa , W.M. Morsi , E.A. Fahmy","doi":"10.1016/j.conbuildmat.2024.139199","DOIUrl":"10.1016/j.conbuildmat.2024.139199","url":null,"abstract":"<div><div>Calcium nitrate, that is a calcium source, is generally used as an accelerating agent, antifreezing admixture, and corrosion inhibitor for Portland cement systems. Metakaolin, which is regularly used as a precursor in the production of geopolymers, lacks calcium. This can cause inefficiency of the geopolymerization process and alter the properties of the cementitious product. To overcome this problem, the potential benefits of adding calcium nitrate as an alternative calcium source for the metakaolin geopolymer mortar were investigated. Different ratios of calcium nitrate, ranging from 0.5 % to 10 %, were added into metakaolin geopolymer mortar. Different tests were conducted to know the effect of calcium nitrate on some properties of metakaolin geopolymer specimens, which were cured in either air or water. Advanced analysis methods were leveraged to unlock deeper meaning from the findings. The results indicated that adding calcium nitrate led to increased flowability and shortened setting time. The addition of 0.5–7 % calcium nitrate increased mechanical strength but reduced transport properties, whilst the addition of 10 % calcium nitrate led to adverse effects. The addition of 0.5–7 % calcium nitrate can mitigate the strength deterioration rate resulting from water curing and decrease drying shrinkage. The incorporation of appropriate ratios of calcium nitrate can form calcium silicate hydrate gel and densify the microstructure.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139199"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142742932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing calcination temperature to improve the compressive strength of coal gasification slag-based alkali-activated materials by reducing carbon content and adjusting polymerization degree

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139284

Xiaowei Gu , Zhihang Hu , Ziyang Hu , Jianping Liu , Qing Wang , Moncef L. Nehdif

{"title":"Optimizing calcination temperature to improve the compressive strength of coal gasification slag-based alkali-activated materials by reducing carbon content and adjusting polymerization degree","authors":"Xiaowei Gu , Zhihang Hu , Ziyang Hu , Jianping Liu , Qing Wang , Moncef L. Nehdif","doi":"10.1016/j.conbuildmat.2024.139284","DOIUrl":"10.1016/j.conbuildmat.2024.139284","url":null,"abstract":"<div><div>The efficient utilization of coal gasification slag (CGS) to prepare alkali-activated materials (AAMs) presents a significant opportunity for addressing the challenges associated with solid waste accumulation and environmental degradation. However, the aluminosilicate glass in CGS is highly polymerized, rendering it challenging to stimulate its potential reactivity. Additionally, the presence of residual carbon impedes the hydration process in AAMs, thereby limiting its applicability. This study focuses on the residual carbon content and polymerization degree of CGS after calcination treatment to overcome these challenges and improve the reactivity of CGS. Results revealed that residual carbon in CGS underwent thermal decomposition, increasing the proportion of aluminosilicate glass components. The degree of polymerization of CGS was reduced by 25 % under calcined conditions at 550°C, whereas at 700°C, CGS recrystallized, and the aluminosilicates were again highly polymerized. The highest reactivity of CGS was observed after calcination at 550°C. The 28 days compressive strength of the prepared AAM paste reached 47.5 MPa, representing an increase of 18.45 % compared to the control. This study innovatively elucidates the physicochemical properties of calcined CGS. It highlights the critical importance of controlling calcination conditions to manage the polymerization degree and phase transformations during carbon removal, thereby enhancing the reactivity and performance of AAMs.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139284"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved thermal insulation, mechanical properties, energy absorption and flame retardancy of bio-based rigid polyurethane foam modified with calcium hydroxystannate

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139251

Xu Zhang , Zhaoqian Wang , Shuai Ding , Zhi Wang , Xua Xie

{"title":"Improved thermal insulation, mechanical properties, energy absorption and flame retardancy of bio-based rigid polyurethane foam modified with calcium hydroxystannate","authors":"Xu Zhang , Zhaoqian Wang , Shuai Ding , Zhi Wang , Xua Xie","doi":"10.1016/j.conbuildmat.2024.139251","DOIUrl":"10.1016/j.conbuildmat.2024.139251","url":null,"abstract":"<div><div>Rigid polyurethane foam (RPUF) is an important energy-saving building material that has attracted much attention. However, it is still a great challenge to effectively prepare RPUF materials with thermal insulation, flame retardant and mechanical properties. In this paper, the non-toxic and halogen-free flame retardant calcium hydroxystannate (CSH) was prepared by a simple and green chemical co-precipitation method, and a low-carbon and environmentally friendly RPUF material was prepared by combining it with RPUF−SO2/Ni3 (10 % wt soybean oil-based polyol and 3 % wt nickel phytate). It was found that SO2/Ni3/CSH4 containing 4 wt% CSH exhibited excellent thermal insulation performance. TG analysis showed that SO2/Ni3/CSH4 had higher initial temperature and activation energy, and its thermal stability was significantly improved. Peak heat release rate (PHRR), total heat release (THR), peak smoke production rate (PSPR), total smoke release (TSR) and Ds were 26.30 %, 17.16 %, 26.67 %, 23.95 % and 11.38 % lower than those of RPUF−SO2/Ni3, respectively. In addition, the compressive strength of SO2/Ni3/CSH4 was increased by 31.10 %, and it also had excellent energy absorption properties. This study provides new ideas for the design of high-performance and multifunctional low-carbon RPUFs, which have potential applications in aerospace and construction.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139251"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the interaction between limestone filler and rice husk ash on the rheological properties of cement composite pastes

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139247

Jialei Wang , Feifei Jiang , Rui Wang

{"title":"Study on the interaction between limestone filler and rice husk ash on the rheological properties of cement composite pastes","authors":"Jialei Wang , Feifei Jiang , Rui Wang","doi":"10.1016/j.conbuildmat.2024.139247","DOIUrl":"10.1016/j.conbuildmat.2024.139247","url":null,"abstract":"<div><div>As an active supplementary cementitious material, rice husk ash (RHA) can improve several properties of cement paste. However, it has a significant negative impact on the flowability of cement pastes. This study aims to improve the rheological properties of cement-RHA paste by adding an additional admixture: limestone filler (LF). The rheological curve was measured using a rheometer, and the effects of LF and RHA on the rheological properties (dynamic and static yield stresses, consistency, and structural build-up) were investigated. The calculation and analysis of water film thickness (WFT) and the interaction forces between the particles in the paste were conducted to reveal the intrinsic mechanism. The results show that LF can effectively eliminate the adverse effect of RHA on rheological properties. When the RHA content is 10 %, the addition of 5 %, 10 %, and 20 % LF reduces the yield stress by 43.86 %, 69.64 %, and 87.11 %, respectively, and decreases the consistency by 28.17 %, 40.85 %, and 73.24 %, respectively. The high porosity of RHA leads to significant water absorption, which affects the WFT between paste particles much more than LF. The WFT decreases with RHA, resulting in a higher yield stress. The higher specific surface area (SSA) of RHA reduces the spacing between paste particles, and the enhanced interactions between particles significantly increase the initial yield stress (20 min). The addition of LF reduces the inter-particle forces and the structural build-up, lowering the yield stress, which results in a good complementary effect between LF and RHA on the rheological properties. This study can provide guidance for the design of mix proportions considering the workability of the cement-LF-RHA composite system.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139247"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142742937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing flame retardancy and smoke suppression of wood via in-situ synthesis of amine-phosphotungstic acid nanoparticles with tunable shapes

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139226

Zhongwei Wang , Yan Qing , Zhu Liu , Shasha Wang , Yiqiang Wu , Shoulu Yang

{"title":"Enhancing flame retardancy and smoke suppression of wood via in-situ synthesis of amine-phosphotungstic acid nanoparticles with tunable shapes","authors":"Zhongwei Wang , Yan Qing , Zhu Liu , Shasha Wang , Yiqiang Wu , Shoulu Yang","doi":"10.1016/j.conbuildmat.2024.139226","DOIUrl":"10.1016/j.conbuildmat.2024.139226","url":null,"abstract":"<div><div>In this work, we developed a new methodology for generating hybrid wood materials through the in-situ hybridization of phosphotungstic acid (HPW) and organic amines at ambient temperature. By selecting specific molecules of organic amines, this innovative process produces rod-like (imidazole) and spherical (triethylamine) amphiphilic organic-PW nanoparticles (NPs) with tunable particle sizes.</div><div>The in-situ synthesis of organic-PW NPs within the wood was verified by series of methods for analysis. The resulting wood samples exhibited remarkable flame retardancy and smoke suppression, as demonstrated by successful fulfilment of the UL-94 test, a remarkable 60.1 % reduction in total smoke production, with a weight percent gain of only 7.5 %.</div><div>Distinct profiles of the pyrolysis products were observed in the organic amine-PW-treated samples compared to pure wood, indicating a shift in the depolymerization pathway from levoglucosenone (LGO) to hydroxymethylfurfural (HMF) in the presence of acid catalyst. Notably, the thermal protection properties of imidazole-PW are higher than those of triethylamine-PW, attributed to the greater stability of cyclic phosphoric acid-imidazole complexes compared to linear phosphoric acid-triethylamine complexes. Our study not only presents an innovative approach to fabricate hybrid wood materials but also demonstrates exceptional flame-retardant and smoke-suppression capabilities, and altered pyrolysis pathways and evaluated intermediate products stability.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139226"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Potentialities of magnesium phosphate cement-based ultra-high-performance concrete in extremely cold weather construction

IF 7.4 1区工程技术

Construction and Building Materials Pub Date : 2024-11-22 DOI: 10.1016/j.conbuildmat.2024.139297

Jie Yuan , Xin Huang , Xin Chen , Zipeng Zhang , Qian Ge , Yang Liu

{"title":"Potentialities of magnesium phosphate cement-based ultra-high-performance concrete in extremely cold weather construction","authors":"Jie Yuan , Xin Huang , Xin Chen , Zipeng Zhang , Qian Ge , Yang Liu","doi":"10.1016/j.conbuildmat.2024.139297","DOIUrl":"10.1016/j.conbuildmat.2024.139297","url":null,"abstract":"<div><div>The aim of this study was to design serviceable ultra-high-performance concrete (UHPC) based on magnesium phosphate cement (MPC) in severely cold weather and investigate the effects of different temperature conditions on UHPC performance, including constant temperatures, natural temperatures, and variations from sub-zero to normal-temperature conditions. The MPC composition was first modified for higher early-age performance, and then the mix proportion of MPC-UHPC was designed based on the modified MPC. Compared with the water content calculated based on the complete consumption of phosphates, optimal mechanical properties were achieved with the lowest water content necessary for acceptable moulding. The designed UHPC was prepared and cured under various low-temperature conditions to investigate its strength development and microstructural maturation. It developed 120 MPa above compressive strength and 24 MPa above flexural strength after 28 d under constant −10 ℃ or the daily fluctuating temperatures of the freezing Harbin winter (−27 to 3 ℃). At low temperatures, the strength was attributed to a combination of MPC hydration, pore solution freezing, and steel fibre reinforcement. However, this study was the first to discover degradation in flexural strength and impact ductility when frozen specimens were moved to warm environments, even though the microstructure was continuously maturing, presenting an increase in hydration products and a decrease in capillary porosity. This paradox was attributed to freezing regression. Finally, the shrinkage and durability of UHPC were tested and verified to meet the requirements of the relevant standards. These findings convincingly demonstrate that MPC-UHPC with an appropriate mix proportion is ideal for winter construction in severely cold regions.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"456 ","pages":"Article 139297"},"PeriodicalIF":7.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0