scholarly journals Strength and dimensional stability of cement-bonded wood waste-sand bricks

2021 ◽  
Vol 67 (No. 12) ◽  
pp. 545-552
Author(s):  
Emmanuel Adelusi ◽  
Olayiwola Ajala ◽  
Reuben Afolabi ◽  
Kayode Olaoye

Conservation of trees which belong to renewable natural resources in developing countries through judicious utilization in building industry has been seriously left unattended to over the years. The utilization of this unprocessed wealth materials which could serve as one of the alternative constituents in construction materials is now a global concern. Therefore, the needs to investigate the strength and water sorption property of wood waste as a partial replacing material in brick production for building construction arise. Sawdust, sand and cement were mixed together at three different mixing ratios of 1 : 1 : 1, 1 : 1 : 2 and 1 : 1 : 3. The brick samples were replicated three times and subjected to water absorption, density and compressive strength tests. The results show that the effect of the equal volume of sand and sawdust with a subsequent increase in the cement portion at each mixing ratio level gave compact bricks without sudden fracture, reduced unit weight of bricks and subsequent lower water sorption properties of the bricks. The bricks show potentials to be used for wall partitioning. The introduction of sawdust also serves as partial sand replacement in concrete brick making.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1190
Author(s):  
Tomasz Sliwa ◽  
Aneta Sapińska-Śliwa ◽  
Tomasz Wysogląd ◽  
Tomasz Kowalski ◽  
Izabela Konopka

The development of civilization, and subsequent increase in the number of new buildings, poses engineering problems which are progressively more difficult to solve, especially in the field of geotechnics and geoengineering. When designing new facilities, particular attention should be paid to environmental aspects, and thus any new facility should be a passive building, fully self-sufficient in energy. The use of load-bearing energy piles could be a solution. This article presents research on the cement slurry formulas with the addition of graphite and graphene, that can be used as a material for load-bearing piles. The proposed solution is to introduce U-tubes into the pile to exchange heat with the rock mass (the so-called energy piles). A comparison of four slurry formulas is presented: the first one consisting mainly of cement (CEM I), graphite, and water, and the remaining three with different percentages of graphene relative to the weight of dry cement. The results could contribute to the industrial application of those formulas in the future.


2021 ◽  
Vol 1020 ◽  
pp. 187-191
Author(s):  
Thongchai Poonpiriya ◽  
Pornrachanee Sawaengkit ◽  
Pornkiat Churnjitapirom ◽  
Sroisiri Thaweboon

Polymethylmethacrylate (PMMA) resin is one of the most commonly used materials for fabricating the base of removable orthodontic appliances. It is known that PMMA resin can promote the adhesion of microbes due to its surface porosity and from long-term use. Vanillin-incorporated PMMA resin has been reported to have antimicrobial effects against Candida albicans. However, the influence of vanillin incorporation on the water sorption and solubility of self-curing orthodontic PMMA resin has not been studied. Objective: To determine the water sorption and solubility of self-curing orthodontic PMMA resin incorporated with different concentrations of vanillin. Materials and methods: Three groups of self-curing orthodontic PMMA resin incorporated with 0.1% and 0.5% vanillin as well as PMMA without vanillin as a control were prepared with ten specimens per group. Water sorption and solubility tests were performed according to ISO 20795-2:2013 specifications. One-way ANOVA and Tukey’s multiple comparison tests at a p<0.05 significance level were used to analyse the data. Results: All three groups met ISO standard requirements. The means of water sorption values showed insignificant differences among the three groups even though the value of the 0.5% vanillin group tended to decrease. Water solubility of the 0.1% vanillin-incorporated group was not significantly different when compared with the control group whereas that of the 0.5% vanillin-incorporated group exhibited a significant lower value when compared with both control and 0.1% vanillin-incorporated groups. This suggests that increasing concentrations of vanillin would decrease the water solubility of PMMA resin. Conclusion: The incorporation of 0.5% vanillin into self-curing orthodontic PMMA resin could significantly reduce its water solubility and showed a trend of less water sorption property. Even with different vanillin concentrations, the water sorption and water solubility properties of PMMA resin were within the ISO standards. Nevertheless, further studies are recommended to determine the amount of residual monomer present in different concentrations of vanillin-incorporated PMMA resin.


Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 288 ◽  
Author(s):  
José A. Orosa ◽  
Diego Vergara ◽  
Ángel M. Costa ◽  
Rebeca Bouzón

Research from the International Energy Agency about indoor ambiences and nearly zero energy buildings (nZEB) in the past has been centred on different aspects such as the prediction of indoor conditions as a function of the weather using laboratory material properties for simulations and real sampled data for validation. Thus, it is possible to use real data for defining behavioural groups of indoor ambiences as a function of real vapour permeability of internal coverings. However, this method is not suitable for modelling it and predicting its behaviour under weather changes, which is of interest to improve the method of selection and use of building construction materials. In this research, artificial intelligence procedures were employed as the first model of permeable coverings material behaviour to provide a newer understanding of building materials and applications for the generation of new control procedures between the mechanical and electronic point of view of building construction materials.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Kun Zhang ◽  
Bairu Lu ◽  
Yihong Wang ◽  
Zhijun Lei ◽  
Zhanshen Yang

According to the latest UN statistics, more than 2 billion people in the world still live in various forms of earthen buildings, including some in China. The variety of earth-based constructional materials is significant among different regions, with each region influencing the selection of local earth construction materials. In this study, earth materials from four regions of China were collected and sorted, with 10 samples from each source, and cube compressive strength tests were performed to analyze the composition and mechanical properties of the four materials, including northeast black earth, southeast red earth, northwest loess, and Xinjiang yellow sand earth. The results showed that significant differences existed in the composition of earth-based constructional materials from different regions, which have influence on the materials’ compressive strength. The order from large to small of compressive strengths was loess, black earth, yellow sandy earth, and red earth. Material load-displacement curves were influenced significantly by the plasticity index, but the overall failure processes of the various samples were basically the same.


2018 ◽  
Vol 10 (12) ◽  
pp. 4688
Author(s):  
Marina Nikolić Topalović ◽  
Milenko Stanković ◽  
Goran Ćirović ◽  
Dragan Pamučar

Research was conducted to indicate the impact of the increased flow of thermal insulation materials on the environment due to the implementation of the new regulations on energy efficiency of buildings. The regulations on energy efficiency of buildings in Serbia came into force on 30 September 2012 for all new buildings as well as for buildings in the process of rehabilitation and reconstruction. For that purpose, the carbon footprint was analyzed in three scenarios (BS, S1 and S2) for which the quantities of construction materials and processes were calculated. The life cycle analysis (LCA), which is the basis for analyzing the carbon life cycle (LCACO2), was used in this study. Carbon Calculator was used for measuring carbon footprint, and URSA program to calculate the operational energy. This study was done in two phases. In Phase 1, the embodied carbon was measured to evaluate short-term effects of the implementation of the new regulations. Phase 2 included the first 10 years of building exploitation to evaluate the long-term effects of the new regulations. The analysis was done for the period of 10 years, further adjustments to the regulations regarding energy efficiency of the buildings in Serbia are expected in accordance with EU directives. The study shows that, in the short-run, Scenario BS has the lowest embodied carbon. In the long-run, after 3.66 years, Scenario S2 becomes a better option regarding the impact on the environment. The study reveals the necessity to include embodied carbon together with the whole life carbon to estimation the impact of a building on the environment.


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