V. Brunello, D. Bersani, L. Rampazzi, A. Sansonetti, C. Tedeschi
{"title":"Gypsum based mixes for conservation purposes: evaluation of microstructural and mechanical features","authors":"V. Brunello, D. Bersani, L. Rampazzi, A. Sansonetti, C. Tedeschi","doi":"10.3989/mc.2020.05019","DOIUrl":"https://doi.org/10.3989/mc.2020.05019","url":null,"abstract":"This paper presents the study of four gypsum mixtures, focusing on the role of both inorganic and organic additives and on the micro-structural features and mechanical properties. Additives have been chosen among those most reported in historical recipes, for example magnesia, lime putty, rabbit glue. The selected mixes refer to gypsum-based materials used in artworks manufacture, such as plasters, mouldings, stuccoworks, pastiglia . Blank reference materials were prepared on purpose according to the specific recipe, in order to verify the final composition and to highlight the hardening mechanisms and the formation of setting compounds. The chemical composition was related to workability properties and final mechanical resistance and the action of additives as retardants was studied with interesting results. For instance, MgO imparts good properties to the mechanical features, especially with regard to the compressive strength characteristics.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47061940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Rivera, A. Orobio, R. Mejía de Gutiérrez, N. Cristelo
{"title":"Clayey soil stabilization using alkali-activated cementitious materials","authors":"J. Rivera, A. Orobio, R. Mejía de Gutiérrez, N. Cristelo","doi":"10.3989/mc.2020.07519","DOIUrl":"https://doi.org/10.3989/mc.2020.07519","url":null,"abstract":"In this study, a clayey soil classified as A-7-5 according ASTM D3282, was stabilized using alkali-activated cementitious materials (AAC) added to the soil dry in percentages of 20 and 30%. Fly ash (F1, F2) with high unburned carbon content (up to 38.76%), hydrated lime (L) and granulated blast furnace slag were used. Unconfined compressive strength and flexural strength at 28 days of curing and the durability after 12 wetting-drying cycles were evaluated. The results were compared with a soil-cement reference mixture. The soil treated with AAC-F1L showed a volume expansion of 0.51% and volume contraction of -0.57% compared with the 0.59% expansion and -0.68% contraction of the soil-cement reference mixture. Additionally, the mass loss after the wetting and drying cycles is only 3.74% which is slightly lower than the mass loss of the soil stabilized with ordinary Portland cement (OPC) (3.86%) and well below the value specified in Colombian regulations (7%).","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43200121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. L. Ferreira, M. A. Anjos, E. F. Ledesma, J. Pereira, A. K. Nóbrega
{"title":"Evaluation of the physical-mechanical properties of cement-lime based masonry mortars produced with mixed recycled aggregates","authors":"R. L. Ferreira, M. A. Anjos, E. F. Ledesma, J. Pereira, A. K. Nóbrega","doi":"10.3989/mc.2020.02819","DOIUrl":"https://doi.org/10.3989/mc.2020.02819","url":null,"abstract":"This study investigated the physical-mechanical effects of cement-lime mortars containing recycled aggregate of construction and demolition waste (CDW). The natural aggregate (NA) was replaced by volume at 25%, 50%, 75% and 100% by mixed recycled aggregate (MRA) obtained from the CDW crushing. Five types of mortars were prepared with a volumetric ratio of 1:1:6 (cement, lime and aggregate) and water/binder ratio based on the fixed consistency of 260 mm. The effects of MRA on fresh and hardened mortars’ properties were analyzed. The results were analyzed using a one-way ANOVA. MRA incorporation improved most of the physical-mechanical properties of mortars tested, except for hardened bulk density, water absorption and porosity. In the long-run, mechanical strengths significantly increased in all compositions, especially those with higher percentages of MRA. The results obtained showed that the use of MRA in masonry mortars is an alternative to reduce the generation of waste and consumption of natural resources.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70316283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of the parameters influencing progress of concrete carbonation depth by using artificial neural networks","authors":"P. Akpınar, I. D. Uwanuakwa","doi":"10.3989/mc.2020.02019","DOIUrl":"https://doi.org/10.3989/mc.2020.02019","url":null,"abstract":"Carbonation is a deleterious concrete durability problem which may alter concrete microstructure and yield initiation of corrosion in reinforcing steel bars. Previous studies focused on the use of Artificial Neural Networks (ANN) for the prediction of concrete carbonation depth and to minimize the need for destructive and elaborated civil engineering laboratory tests. This study aims to provide improved accuracy of simulation and prediction of carbonation with an ANN architecture including eighteen input parameters employing alternative Scaled Conjugate Gradient (SCG) function. After ensuring a promising value of the coefficient of correlation as high as 0.98, the influence of proposed input parameters on the progress of carbonation depth was studied. The results of this parametric analysis were observed to successfully comply with the conventional civil engineering experience. Hence, the employed ANN model can be used as an efficient tool to study in detail and to provide insights into the carbonation problem in concrete.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42312946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pokpong Rattanachu, I. Karntong, Weerachart Tangchirapat, C. Jaturapitakkul, Prynia Chindaprasirt
{"title":"Influence of bagasse ash and recycled concrete aggregate on hardened properties of high-strength concrete","authors":"Pokpong Rattanachu, I. Karntong, Weerachart Tangchirapat, C. Jaturapitakkul, Prynia Chindaprasirt","doi":"10.3989/MC.2018.04717","DOIUrl":"https://doi.org/10.3989/MC.2018.04717","url":null,"abstract":"This research aimed to use of bagasse ash as a cement replacement in high-strength recycled aggregate concrete (HS-RAC). Crushed limestone was replaced with 100% recycled concrete aggregate (RCA) and the ground bagasse ash (GBA) was used to partially replace ordinary Portland cement (OPC) at 20, 35 and 50%wt of binder to cast HS-RAC. The results indicated that the replacing of crushed limestone with RCA had a negative impact on the properties of the concrete. Increasing the amount of GBA in HS-RAC resulted in a decrease in density and an increase in the volume of permeable pore space. The concrete mixtures prepared with 20%wt GBA replacement of OPC promoted greater the compressive strength than the conventional concrete (CT concrete) at 90 days or more. HS-RAC with GBA (up to 50%) was more durable in terms of chloride ion penetration resistance, although it had lower compressive strength than the CT concrete.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46524135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. González-Fonteboa, S. Seara-Paz, J. Brito, Iris González-Taboada, F. Martínez-Abella, R. Vasco-Silva
{"title":"Recycled concrete with coarse recycled aggregate. An overview and analysis","authors":"B. González-Fonteboa, S. Seara-Paz, J. Brito, Iris González-Taboada, F. Martínez-Abella, R. Vasco-Silva","doi":"10.3989/MC.2018.13317","DOIUrl":"https://doi.org/10.3989/MC.2018.13317","url":null,"abstract":"The construction field has contributed to environmental degradation, producing a high amount of construction and demolition waste (C&D waste) and consuming large volumes of natural resources. In this context, recycled concrete (RC) has been recognised as a means to preserve natural resources and reduce space for waste storage. During the last decades, many researchers have developed works studying different recycled concrete properties. \u0000This review focuses on structural RC made with coarse recycled aggregate from concrete waste. The main objective is to provide a state of the art report on RC’s properties and an analysis on how to predict them taking into account relevant research works. Moreover, the study tries to collect and update RC findings, proposing equations to define RC’s performance, in terms of mechanical strength, modulus of elasticity, stress-strain, creep and shrinkage.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46033513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of hybrid fibers, calcium carbonate whisker and coarse sand on mechanical properties of cement-based composites","authors":"M. Cao, L. Li, Mehran Khan","doi":"10.3989/MC.2018.01717","DOIUrl":"https://doi.org/10.3989/MC.2018.01717","url":null,"abstract":"Nowadays researchers are developing a new hybrid fiber reinforced cement-based composites (HyFRCC). The new HyFRCC can restrain micro-cracking, improves compressive and flexural performance of beams by addition of calcium carbonate (CaCO 3 ) whisker, polyvinyl alcohol (PVA) fiber and steel fiber. In this work, a mix optimization procedure is shown for multi-scale HyFRCC, with steel, PVA fiber and CaCO 3 whisker. The new HyFRCC is explored with addition of coarse sand to further improve its mechanical properties. Additionally, the flexural performance of beam and slabs has been investigated to optimize sand gradation and fiber combination in new HyFRCC. The compressive strength, flexural strength, flexural behavior, flexural toughness, equivalent flexural strength and deflection-hardening behavior of beams and slabs are improved with optimized content of sand gradation, fibers and CaCO 3 whisker. The HyFRCC slab with 1.5% steel fiber, 0.4% PVA fiber, 1% CaCO 3 whisker and optimized coarse sand showed overall best properties.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49426236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficiency of self-healing cementitious materials with encapsulated polyurethane to reduce water ingress through cracks","authors":"B. V. Belleghem, K. Tittelboom, N. Belie","doi":"10.3989/MC.2018.05917","DOIUrl":"https://doi.org/10.3989/MC.2018.05917","url":null,"abstract":"Cracks in reinforced concrete elements can cause major durability issues due do the accelerated ingress of aggressive substances. In this study, repair of cracks was addressed by incorporating encapsulated polyurethane based healing agents in the cementitious material as an autonomous healing mechanism. \u0000 \u0000Capillary sorption tests showed that a high viscosity healing agent could reduce the water ingress in cracked mortar, but a large scatter in the results was found, resulting in a large range of healing efficiencies (18 – 108%). The low viscosity polyurethane showed a more complete and consistent crack healing. Healing efficiencies ranging from 95 to 124% were observed (crack width up to 295 μm). The proposed healing mechanism is very effective in blocking the ingress of water. This will enhance the durability of cementitious materials and consequently extend their lifetime.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49427979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. M. Pereira, J. Moraes, M. Moraes, J. Akasaki, M. Tashima, L. Soriano, J. Monzó, J. Payá
{"title":"Valorisation of sugarcane bagasse ash (SCBA) with high quartz content as pozzolanic material in Portland cement mixtures","authors":"A. M. Pereira, J. Moraes, M. Moraes, J. Akasaki, M. Tashima, L. Soriano, J. Monzó, J. Payá","doi":"10.3989/MC.2018.00617","DOIUrl":"https://doi.org/10.3989/MC.2018.00617","url":null,"abstract":"The authors would like to thank the Ministerio de Educacion, Cultura y Deporte of Spain (Cooperacion Interuniversitaria Program with Brazil, Project PHB-2011-0016-PC), CAPES-Brazil (Project CAPES/DGU No. 266/12), CNPq (Project 401724/2013-1) and Electron Microscopy Service of the Universitat Politecnica de Valencia.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46906822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Isothermal water vapour permeability of concrete with different supplementary cementitious materials","authors":"N. Alderete, Y. V. Zaccardi, A. D. Maio, N. Belie","doi":"10.3989/MC.2018.02517","DOIUrl":"https://doi.org/10.3989/MC.2018.02517","url":null,"abstract":"Water vapour permeability (WVP) is a key parameter for the sustainable thermal conditioning of buildings. The study of the WVP in concrete with supplementary cementitious materials (SCMs) allows for the design of structures with improved durability and sustainability. To our knowledge, there is insufficient experimental data in the literature regarding the WVP of concrete with SCMs. \u0000 \u0000WVP tests were made on concrete mixes containing ground granulated blast-furnace slag (GGBFS) and limestone powder (LP) as a partial replacement for ordinary Portland cement, and of concrete mixes containing pozzolanic cement (NP). Results from three moisture gradients show that GGBFS induces the greatest reduction in WVP, followed by the NP. LP shows a diluting effect of the binder, which could be compensated by GGBFS in the ternary blend. From the comparison between the WVP and the capillary sorption rate, the influence of the SCMs on the connectivity of the smallest pores is assessed.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2018-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41331309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}