The use of by-products from agricultural production as stabilizers in concrete and mortar in developing countries could result in numerous benefits. These by-products are readily available, cheap, ...and have a lesser carbon footprint. As Portland cement prices keep rising, the search for alternatives to sustainable construction materials is necessary. Cashew apples are left on cashew farms as waste material after the nuts have been removed due to lack of utilization. In this study, the properties of sandcrete blocks produced with cashew apple ash (CAA) as a partial replacement for cement were investigated. A total of 180 block specimens of size 100 × 100 × 130 mm were prepared from six different mortar mixes of control, 5, 10, 15, 20, and 25% CAA replacement of cement by weight were prepared. Results revealed that the highest compressive and tensile strengths after 28 days of curing CAA blocks were 11.45 and 1.08 N/mm
respectively. The best water absorption resistance obtained was 2.66%. The study recommends the use of 5% CAA replacement of cement to block manufacturers for use in manufacturing sandcrete blocks. This study is useful because the cashew apple waste ash used as an alternative material to cement in sandcrete block production will be beneficial to the environment and may also save the cost of production of sandcrete blocks.
Stabilisation of earth-based materials continues to gain attention among researchers in the field of construction. This study investigates the influence of coconut fibres and lime on the properties ...of soil-cement mortar. Fibres of 0.2–0.8 %; the lime of 0–15 %; cement of 5 % by weight of soil were used and tested for density, water absorption, compressive strength, tensile strength and SEM/EDS. There were improved density, water-resistance and erosion of the specimen. The optimum strength was recorded at 0.2 % fibre and 5 % lime addition of the specimen. The study concludes that coconut fibres and lime positively influences soil-cement mortar properties for construction application.
Compaction of blocks contributes significantly to the strength properties of compressed earth blocks. This paper investigates the influence of compacting rates on the properties of compressed earth ...blocks. Experiments were conducted to determine the density, compressive strength, splitting tensile strength, and erosion properties of compressed earth blocks produced with different rates of compacting speed. The study concludes that although the low rate of compaction achieved slightly better performance characteristics, there is no statistically significant difference between the soil blocks produced with low compacting rate and high compacting rate. The study demonstrates that there is not much influence on the properties of compressed earth blocks produced with low and high compacting rates. It was further found that there are strong linear correlations between the compressive strength test and density, and density and the erosion. However, a weak linear correlation was found between tensile strength and compressive strength, and tensile strength and density.
This study investigated the properties of cement mortar with lime reinforced with plantain pseudostem fibres. Experimental specimens with 0, 0.25, 0.5, 0.75, and 1% fibre contents by weight of sand ...and 10% lime content by weight of cement were prepared and tested on 7, 14, 21, and 28 days of curing for density, tensile strength, compressive strength, SEM, and EDS. The 0.25% plantain pseudostem fibre reinforced mortar achieved 23.4% compressive strength improvement over unreinforced mortar specimens. There was between 6.89 and 13.80% increase in tensile strength of the plantain pseudostem fibre reinforced mortar over the unreinforced mortar specimens. A positive linear correlation was found between the compressive strength and tensile strength of cement mortar reinforced with plantain pseudostem fibres and lime with coefficient of determinant (R2) values between 0.909 and 0.869. It was also observed that the plantain pseudostem fibre reinforced mortar specimen had some microcracks and voids from the SEM analysis. Furthermore, EDS analysis showed the presence of calcium silicate hydrate with a Ca/Si ratio of between 1.02 and 2.49, and Al/Si ratio of between 0.76 and 0.81 as the main oxide. It therefore concluded that the incorporation of plantain pseudostem fibre and lime positively influenced the properties of the cement mortar with the 0.25% fibre content being recommended for construction application.
The construction of high-rise buildings has increased the production and demand of ribbed mild steel reinforcing bars (RMSRBs) in Ghana. This study aimed at investigating the strength properties of ...RMSRBs manufactured in Ghana from scrap metals. Three steel-producing companies were considered for this study. A total of 90 samples of 12, 16, and 20mm diameters with lengths of 500, 50, and 20mm were used for the study. The prepared specimens were subjected to tensile strength test, chemical composition analysis, micro-hardness test, and microstructure analysis. The results indicate that the average tensile strength of between 576.00 and 768.40N/mm2 were above the minimum tensile strength of 250N/mm2 recommended by ASTM E8/E8M-16a. The carbon equivalent values (CEVs) of between 0.287 and 0.333% obtained were almost within the range of 0.3 to 0.55% recommended by ASTM A706/A706M-09b. It was also identified that the average Vickers hardness values of between 255.76 and 295.38HV were acceptable. The microstructural images showed good distribution of the pearlite and ferrite of the core. One Way ANOVA results indicated that the differences in the tensile strength values for 12mm (p-value ˂0.000) and 16mm (p-value =0.001) were statistically significant, however, the 20mm (p-value =0.138) was not statistically significant. The study, therefore, concludes that the strength properties of the 12, 16, and 20mm diameters of the RMSRBs produced by the three different companies in Ghana meet the standard requirements, and are recommended for use by contractors for the production of reinforced concrete.
Studies on sustainable construction materials are on the rise with their environmental, social, and economic benefits. This study identifies the key indicators for measuring sustainable construction ...materials. The design used for the study was that of a survey which relied on a questionnaire with five-point Likert scale to generate data for the analysis. For this purpose, 25 indicators from the three dimensions (environmental, social, and economic) identified from the literature were presented to the respondents in a structured questionnaire, and responses were collected and analysed using SPSS. The study identified three key environmental indicators for measuring sustainable construction materials, and these indicators are human toxicity, climate change, and solid waste. Furthermore, adaptability, thermal comfort, local resources, and housing for all were identified as the four key social indicators for sustainable construction materials. In addition, maintenance cost, operational cost, initial cost, long-term savings, and life span were found to be the five key economic indicators for measuring sustainable construction materials. The study therefore suggests that these twelve indicators should be considered in future studies that seek to measure sustainable construction materials.
The use of burnt bricks is gradually becoming popular in the Ashanti region in Ghana. This is evident with the increased number of burnt brick manufacturing sites in the region. However, the quality ...of the manufactured burnt bricks is not known. The study aims at assessing the quality of burnt bricks produced in the Ashanti Region of Ghana. 200 bricks samples were randomly selected from five brick production sites for their properties to be determined and compared with standards and previous studies’ requirements. The bricks were physically examined for regular shape, size variation, and surface crack; and tested for dry density, compressive strength, split tensile strength, water absorption, and abrasion coefficient. The bricks were observed to have regular surfaces with some visible cracks and reduced size variations beyond the tolerance level. The densities of the burnt bricks (1548.84–1988.61 kg/m3) were found to be satisfactory. The compressive strength of 10.27–19.71 MPa, and split tensile strengths of 1.50–2.88 MPa were within the class designation for burnt bricks. The water absorption of 3.30–8.25%, and abrasion resistance of 1.48–2.04 cm2/g met the requirement of burnt bricks. The study concludes that the physical and mechanical properties of the brunt bricks produced in the Ashanti Region of Ghana are of acceptable quality. A recommendation is made to the manufactures to put in place proper quality control measures to improve some of the physical properties such as size variation and cracking defects of the burnt bricks.
Waste wigs are often disposed off in their volume on landfills, thus constituting a nuisance to the environment. Recycling these wigs in masonry bricks is a way via which they can be recycled and ...reused. On such premise, waste wig fiber (WWF) was recycled by incorporating into the cement-sand-clay composite mix for masonry bricks production. The challenges masonry bricks face include shrinkage and water susceptibility; hence, the contributory effect of WWF on physio-hydric properties was assessed in this study. Sample preparation entailed blending of cement, sand, clay soil, and waste wig fiber. The control mix was prepared by commixing clay with 10% cement (by clay volume) and 20% sand (by clay volume). Other mix proportions were reinforced with 1, 2, 3, 4, and 5% WWF by clay volume. Prepared composite brick samples were cured for 28 and 56 days and tested for physio-hydric properties. Results revealed WWF contributed significantly in improving hydro-resisting properties by minimizing porosity, water and moisture absorption, capillary suction, and water permeability. Furthermore, WWF contributed to dimensional stability by reducing shrinkages and weight loss. Hydration time impacts significantly in reducing apparent porosity, water permeability coefficient, moisture and water absorption, and capillary suction coefficient and increasing apparent density, weight loss, linear, and volumetric shrinkage. The general outcome depicts that WWF showed promising performance in bricks developed in enhancing water and moisture susceptibility resistance and promoting mass and dimensional stability, hence can be employed in reinforcing cement adobe bricks at an optimum mix of 5% vol fraction.
This study aimed to partially replace ordinary Portland Cement (OPC) with sawdust burnt ash (SDBA) in making interlocking laterite soil blocks. Four sets of mixes were considered: 0, 10, 20, and ...30 wt%. Mix proportion was 1:6 (cement + SDBA: laterite) with a 0.70 water-to-cement ratio. 192 specimens of size 185 mm × 220 mm × 120 mm were produced and cured at normal temperature and humidity under shady and sunny conditions for 7, 14, 21 and 28 days. The research targeted four tests using 48 specimens apiece at these ages: bulk density, compressive strength, traction, and water absorption. A minimum density of 2123 kg/m3 and a maximum density of 2288 kg/m3 were recorded at 28 days when 10% and 20% of SDBA respectively replaced cement. Average compressive strengths at 0, 10, 20, 30 wt% of SDBA were respectively 6.20 ± 0.213, 6.52 ± 0.268, 6.32 ± 0.231 and 5.73 ± 0.339 N/mm2 at 28 days. Also, water absorption rates increased as the contents of SDBA replacement were increased. It was also shown that 20 wt% of SDBA is the optimum replacement level for OPC to make interlocking blocks and achieve desirable engineering properties. Though strength properties of compression and traction did not significantly improve, SDBA’s pozzolanic and cementitious properties could prevent the blocks from premature failure. Conclusively, interlocking blocks failed to significantly outperform reference samples (0%) after 28 days of testing. However, 20 wt% of SDBA on day 21 produced an average compressive strength of 6.22 ± 0.042 N/mm2 satisfying minimum allowable sandcrete blocks strength of 2.75 N/mm2 for load-bearing masonry structures per Ghana Building Code.
Landcrete interlocking blocks production process. Display omitted
•Sawdust ash (SDBA) addition slightly improved interlocking blocks’ strength properties.•20% SDBA can optimally replace cement to achieve desirable densities in blocks production.•Water absorption and strength increased as SDBA replacement for cement was increased.•Cementitious property (natural pozzolan) in SDBA foiled interlocking blocks from easy failure.•Products qualified as lightweight blocks for use in load-bearing walls fabrication in Ghana.
AbstractThe aim of this study was to investigate the individual and combined effect of kaolin clay (KC) and shea nut shell particles (SSP) on the physical, strength, and durability properties of ...concrete. The cement content was replaced with up to 20% KC, and the fine aggregate content was replaced with up to 40% SSP. The concrete samples were cured for 7, 14, 28, and 90 days, and tested. The total SiO2+Al2O3+Fe2O3 content of the KC studied was 88.23%; hence, it possesses pozzolanic properties. Initial and final setting times of the KC pastes steadily increased to 154 min and 325 min at the 20% KC representing 37.5% and 14.4% increase over the control. The control mix obtained a workability value of 102 mm, and decreased steadily to 68 mm at the 20% KC and 40% SSP concrete mix, representing 50% reduction. Maximum compressive and split tensile strength values of 25.97 N/mm2 and 4.14 N/mm2 were obtained at the 15% KC and 30% SSP concrete, representing 9% and 5% increase over the control concrete respectively in 90 days curing. Furthermore, concrete with 15% KC and 30% SSP recorded 61.5% and 22.1% decrease in water absorption and sulfate attack, over the control concrete respectively in 90 days curing. It is concluded that the addition of KC and SSP positively influenced the physical, strength and durability of concrete, and therefore recommend 15% KC and 30% SSP replacements of cement and fine aggregate respectively for concrete production.
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