S. Poh-Yap, U. Johnson-Alengaram, K. Hung-Mo, M. Zamin-Jumaat
{"title":"High strength oil palm shell concrete beams reinforced with steel fibres","authors":"S. Poh-Yap, U. Johnson-Alengaram, K. Hung-Mo, M. Zamin-Jumaat","doi":"10.3989/MC.2017.11616","DOIUrl":"https://doi.org/10.3989/MC.2017.11616","url":null,"abstract":"The utilization of lightweight oil palm shell to produce high strength lightweight sustainable material has led many researchers towards its commercialization as structural concrete. However, the low tensile strength of Oil Palm Shell Concrete (OPSC) has hindered its development. This study aims to enhance the mechanical properties and flexural behaviours of OPSC by the addition of steel fibres of up to 3% by volume, to produce oil palm shell fibre-reinforced concrete (OPSFRC). The experimental results showed that the steel fibres significantly enhanced the mechanical properties of OPSFRC. The highest compressive strength, splitting tensile and flexural strengths of 55, 11.0 and 18.5 MPa, respectively, were achieved in the OPSFRC mix reinforced with 3% steel fibres. In addition, the flexural beam testing on OPSFRC beams with 3% steel fibres showed that the steel fibre reinforcement up to 3% produced notable increments in the moment capacity and crack resistance of OPSFRC beams, but accompanied by reduction in the ductility.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"142"},"PeriodicalIF":2.1,"publicationDate":"2017-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48881462","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":"Preparation of β-belite using liquid alkali silicates","authors":"P. Koutník","doi":"10.3989/MC.2017.10816","DOIUrl":"https://doi.org/10.3989/MC.2017.10816","url":null,"abstract":"The aim of this study is the preparation of β-belite by a solid-state reaction using powdered limestone, amorphous silica and liquid alkali silicates. The raw materials were blended, the mixtures were agglomerated and then burnt. The resulting samples were characterized by X-ray diffraction analysis and scanning electron microscopy. Free lime content in the β-belite samples was also determined. The effects of CaO/SiO 2 ratio (1.6–2.1), burning temperature (800–1400 °C), utilization of different raw materials (silica fume, synthetic silica, potassium silicate, sodium silicate, potassium hydroxide) and burning time (0.5–16 h) on free lime content and mineralogical composition were investigated. The purest ?-belite samples were prepared from a mixture of powdered limestone, silica fume and liquid potassium silicate with a ratio CaO/SiO 2 = 2 by burning at temperatures between 1100 and 1300 °C for more than 2 h. Decreasing of the CaO/SiO 2 ratio led to rankinite formation and lower a burning temperature led to the formation of wollastonite.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"140"},"PeriodicalIF":2.1,"publicationDate":"2017-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43884967","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":"Characterization of quality recycled gypsum and plasterboard with maximized recycled content","authors":"Ana Jiménez-Rivero, J. García-Navarro","doi":"10.3989/MC.2017.06016","DOIUrl":"https://doi.org/10.3989/MC.2017.06016","url":null,"abstract":"The quality of secondary materials is imperative to promote a circular economy. In order to improve the way in which the quality of recycled gypsum is assessed, European guidelines on recycled gypsum (RG) quality criteria have been outlined in the framework of the Life+ Gypsum to Gypsum (GtoG) project. Such GtoG guidelines, along with the European Standard on gypsum plasterboard EN 520, provided the basis for this study. During the GtoG project, gypsum recycling and plasterboard manufacturing processes were monitored by testing the gypsum feedstock and the plasterboard produced. The aim of this paper is to discuss the results obtained on relevant parameters that characterize gypsum as a secondary raw material, as well as the resulting product. The minimum requirements were fulfilled by 56% of the RG samples and 86% of the plasterboard with increased RG.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"137"},"PeriodicalIF":2.1,"publicationDate":"2017-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42282491","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. P. Pérez-Fortes, M. J. Varas-Muriel, Pedro Castiñeiras
{"title":"Utilización de técnicas petrográficas para evaluar los efectos inducidos del NaCl, condiciones climáticas extremas y el paso del tráfico en las superficies de las carreteras españolas","authors":"A. P. Pérez-Fortes, M. J. Varas-Muriel, Pedro Castiñeiras","doi":"10.3989/mc.2017.07516","DOIUrl":"https://doi.org/10.3989/mc.2017.07516","url":null,"abstract":"The asphalt surface layer is the most exposed to weather and traffic conditions on roads, especially those subjected to winter maintenance. Therefore, a deep knowledge of the mechanisms which can damage this layer is necessary to improve its design, construction and long-term use. With this purpose, two types of asphalt mixtures used on roads from NW Spain were subjected to durability tests (freezing-thaw and thermal-stress) with a saturated NaCl solution. After the durability tests, a wheel tracking test was performed on the samples, and the resultant material was analyzed by optical polarized light and fluorescence microscopy. This analysis showed that the binder-aggregate low adhesion was the main responsible of the asphalt mixture damage. This damage was concentrated in the aggregates because the binder acted as an impermeable wall. Consequently, the NaCl solution penetrated and degraded the aggregates quickly and strongly.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"138"},"PeriodicalIF":2.1,"publicationDate":"2017-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70316093","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}
M. Silva, M. Cunha, A. Pinho-Ramos, B. S. D. Fonseca, F. Pinho
{"title":"Accelerated action of external sulfate and chloride to study corrosion of tensile steel in reinforced concrete","authors":"M. Silva, M. Cunha, A. Pinho-Ramos, B. S. D. Fonseca, F. Pinho","doi":"10.3989/MC.2017.10116","DOIUrl":"https://doi.org/10.3989/MC.2017.10116","url":null,"abstract":"Corrosion of the reinforcing steel may cause significant loss of strength of reinforced concrete structures. The study focuses on accelerating such corrosion and examining the degradation of (i) the compressive strength of concrete due to sodium sulfate in a wet atmosphere; and (ii) the flexural strength by a solution of sodium sulfate and sodium chloride. Three types of concrete were used and different beam specimens were reinforced by steel rebars of different diameters (6, 8 and 10mm), part of the beams being pre-cracked. The concrete with least strength allowed higher sulfate penetration along the entire process and the compressive strength increased slightly, possibly due to lower porosity of concrete after contamination. The results of the flexural tests showed decrease of strength in all cases. Pre-cracked beams exhibited smaller influence of porosity of concrete. Beams with 6mm rebars showed the largest loss of strength due to the contamination and corrosion process","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"141"},"PeriodicalIF":2.1,"publicationDate":"2017-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49215020","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":"Comparison of strength and durability characteristics of a geopolymer produced from fly ash, ground glass fiber and glass powder","authors":"H. Rashidian-Dezfouli, P. Rangaraju","doi":"10.3989/MC.2017.05416","DOIUrl":"https://doi.org/10.3989/MC.2017.05416","url":null,"abstract":"Strength and durability characteristics of geopolymers produced using three precursors, consisting of fly ash, Ground Glass Fiber (GGF), and glass-powder were studied. Combinations of sodium hydroxide and sodium silicate were used as the activator solutions, and the effect of different sodium and silica content of the activators on the workability and compressive strength of geopolymers was investigated. The parameters used in this study were the mass ratio of Na2O-to-binder (for sodium content), and SiO2-to-Na2O of the activator (for silica content). Geopolymer mixtures that achieved the highest compressive strength from each precursor were assessed for their resistance to alkali-silica reaction and compared against the performance of portland cement mixtures. Test results revealed that GGF and fly ash-based geopolymers performed better than glass-powder-based geopolymer mixtures. The resistance of GGF-based and fly ash-based geopolymers to alkali-silica reaction was superior to that of portland cement mixtures, while glass-powder-based geopolymer showed inferior performance.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"136"},"PeriodicalIF":2.1,"publicationDate":"2017-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47487691","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}
L. Pirozzolo, M. Sol-Sánchez, F. Moreno-Navarro, G. Martínez-Montes, M. Rubio-Gámez
{"title":"Evaluation of bituminous sub-ballast manufactured at low temperatures as an alternative for the construction of more sustainable railway structures","authors":"L. Pirozzolo, M. Sol-Sánchez, F. Moreno-Navarro, G. Martínez-Montes, M. Rubio-Gámez","doi":"10.3989/MC.2017.04816","DOIUrl":"https://doi.org/10.3989/MC.2017.04816","url":null,"abstract":"Hot bituminous mixtures are becoming widely used in modern railway tracks in the sub-ballast layer. The reason is that these materials allow for both an increase in bearing capacity and greater protection of the substructure respect the traditional granular sub-ballast. Despite these advantages, the fact that these materials are manufactured at a temperature of 160°C means that their application can lead to an important increase in construction costs, pollution and energy consumption. This paper aims to study the possibility of using WMA manufactured at lower temperatures, as bituminous sub-ballast, in order to save energy and reduce emissions throughout the production process, as well as diminish the global costs of this layer. To this end, this study focuses on a comparison of the mechanical behaviour of warm and hot bituminous mixtures as sub-ballast under various loading conditions. The results indicate that WMA offers mechanical behaviour that is comparable to conventional HMA.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"128"},"PeriodicalIF":2.1,"publicationDate":"2017-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47111719","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":"Impact of using lightweight eco-bricks as enclosures for individual houses of one story on zones of high seismicity","authors":"D. Dominguez, V. Munoz, V. L. Muñoz","doi":"10.3989/MC.2017.03316","DOIUrl":"https://doi.org/10.3989/MC.2017.03316","url":null,"abstract":"Fired clay bricks are widely developed by focusing on the use of several wastes with the aim of obtaining lightweight materials. Despite research having provided positives experiences, most of these showed an important reduction of compression strength. This issue must be highlighted in particular, when seismic areas are considered. However, despite compression strength decreases in some cases the energy that can be absorbed by the brick might be increased. Hence, this paper tests and shows physical and mechanical properties of newly fired clays made by adding different percentages of sawdust. Results are used for calculating the response of an individual one-story house to medium intensity earthquakes. It is concluded that the use of bricks, with up to 5% sawdust added, is an ecological way for recycling these agro-wastes, while its behaviour against earthquakes performs better than other solutions, such as common perforated bricks.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"133"},"PeriodicalIF":2.1,"publicationDate":"2017-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46332413","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":"Small-sized reverberation chamber for the measurement of sound absorption","authors":"R. D. Rey, J. Alba, L. Berto, A. Gregori","doi":"10.3989/MC.2017.07316","DOIUrl":"https://doi.org/10.3989/MC.2017.07316","url":null,"abstract":"This paper presents the design, construction, calibration and automation of a reverberation chamber for small samples. A balance has been sought between reducing sample size, to reduce the manufacturing costs of materials, and finding the appropriate volume of the chamber, to obtain reliable values at high and mid frequencies. The small-sized reverberation chamber, that was built, has a volume of 1.12 m 3 and allows for the testing of samples of 0.3 m 2 . By using diffusers, to improve the diffusion degree, and automating measurements, we were able to improve the reliability of the results, thus reducing test errors. Several comparison studies of the measurements of the small-sized reverberation chamber and the standardised reverberation chamber are shown, and a good degree of adjustment can be seen between them, within the range of valid frequencies. This paper presents a small laboratory for comparing samples and making decisions before the manufacturing of larger sizes.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"139"},"PeriodicalIF":2.1,"publicationDate":"2017-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48505149","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. Blanco, P. Pujadas, Cristina Fernández, S. Cavalaro, A. Aguado
{"title":"Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete","authors":"A. Blanco, P. Pujadas, Cristina Fernández, S. Cavalaro, A. Aguado","doi":"10.3989/MC.2017.05316","DOIUrl":"https://doi.org/10.3989/MC.2017.05316","url":null,"abstract":"Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO 2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"67 1","pages":"135"},"PeriodicalIF":2.1,"publicationDate":"2017-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47809130","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}