Compressive Strength of Volcanic Ash/Ordinary Portland Cement Laterized Concrete

This study investigates the effect of partial replacement of cement with volcanic ash (VA) on the compressive strength of laterized concrete. A total of 192 cubes of 150mm dimensions were cast and cured in water for 7, 14, 21, and 28 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively, while a control mix of 28-day target strength of 25 N/mm2 was adopted. The results show that the density and compressive strength of concrete decreased with increase in volcanic ash content. The 28-day, density dropped from 2390 kg/m3 to 2285 kg/m3 (i.e. 4.4% loss) and the compressive strength from 25.08 N/mm2 to 17.98 N/mm2 (i.e. 28% loss) for 0-30% variation of VA content with no laterite introduced. The compressive strength also decreased with increase in laterite content; the strength of the laterized concrete however increases as the curing age progresses

Influence of Curing Age and Mix Composition on Compressive Strength of Volcanic Ash Blended Cement Laterized Concrete

This study investigates the influence of curing age and mix proportions on the compressive strength of volcanic ash (VA) blended cement laterized concrete. A total of 288 cubes of 100mm dimensions were cast and cured in water for 3, 7, 28, 56, 90 and 120 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively while a control mix of 28-day target strength of 25N/mm2 (using British Method) was adopted. The results show that the compressive strength of the VA-blended cement laterized concrete increased with the increase in curing age but decreased as the VA and laterite (LAT) contents increased. The optimum replacement level was 20%LAT/20%VA. At this level the compressive strength increased with curing age at a decreasing rate beyond 28 days. The target compressive strength of 25N/mm2 was achieved for this mixture at 90 days of curing. VA content and curing age was noted to have significant effect (α 0.5) on the compressive strength of the VA-blended cement laterized concrete

An Investigation into the Pozzolanic properties of Dutsin Dushowa volcanic ash of Jos Plateau

This study investigates the pozzolanic properties of the volcanic ash (VA) sample obtained from Dutsin Dushowa, Kerang in Mangu Local Government Area of Plateau State. Chemical Analysis of the VA sample was carried out to determine the oxide contents, so also were some physical properties (specific gravity, fineness, soundness, consistency, and water requirement and setting times (initial and final)) tests carried out on the VA sample and VA-blended cement samples. The result reflects a Silicon Dioxide (SiO2) content of 41.13% and a total Silicon Dioxide, Iron Oxide, and Aluminium Oxide (SiO2+Fe2O3+Al2O3) content of 70.99%. The VA sample has a specific gravity value of 2.65 kg/m3 while the VA-blended cement was noted to be finer than the control (Dangote - Obajana) cement. The soundness of the VA-blended cement ranged between 1.5 and 4.5 for replacement levels of 0% to 30%. The consistency increased from 30.0% to 31.5% as VA substitution increased from 0% to 30%. The water required for a standard consistency was noted to increase as the VA content increased. The initial and final setting times increased from 50 to 105 minutes and 135 to 180 minutes respectively for this replacement levels. All the VA-blended cements thereby satisfy the various code requirements up to the 30% replacement levels

Effect of Batching Methods on the fresh and hardened properties of Concrete

This paper investigated the effect of batching by mass and volume on concrete’s compressive strength and workability. Influence of mix proportion at five levels and various water-cement ratios were also studied. All samples were cured by complete immersion in water and tested up to 28 days. The results indicated higher workabilities for concrete batched by mass than concrete batched by volume at all w/c ratios and mix proportions investigated. The workability increased with increase in w/c ratios in both methods. The compressive strength results showed that for rich structural mixes (1:1:2 and 1:1.5:3), concrete batched by mass had 20 % and 6 % strength increases respectively over the concrete batched by volume. Ordinary structural mix (1:2:4) had 14 % increase while non-structural mixes (1:3:6 and 1:4:8) had 8 % and 6 % increases respectively. In all cases, concrete batched by mass had better fresh and hardened properties of concrete

Performance assessment of Makurdi burnt Bricks.

This work involved onsite observation of the production process; determination of physical properties and chemical composition of the soil sample used for production of Makurdi burnt bricks (MBB). A total of 22 brick specimens, of the MBB was examined in the laboratory for compressive strength, water absorption and abrasion resistance. The results reveal the soil sample as a true laterite having a Silica-Sesquioxide ratio of 1.01, Silica content of 42.95 and clay content of 27.38 and total clay + silt content of 30.78. The Atterberg’s limit test gave the liquid limit as 36.79; plastic limit, 26.11and plastic index, 10.68. Compressive strength was 3.46 N/mm2 and 11.75 N/mm2 for Samples A and B respectively; Average water absorption for Sample B (16.49%) was double that of Sample A (8.58%) while the Abrasion resistance ability of Sample B (33.67%) was four times better than Sample A (9.32%)

A Review of Pozzolana in Nigeria: Current State and Exploratory Assessment for Commercialization in Construction

Many researches have been conducted on pozzolanic materials in Nigeria, mainly from agricultural and industrial wastes, and calcination of natural deposit material as clay. Many conclusions on these researches indicate they can improve the quality of concrete produced with them, resulting in the production of sustainable concrete. They possess the potential for more affordable construction and reduce the ill reputation concrete has garnered over the years due to its growing carbon footprint. The utilization of these wastes in concrete also reduces the pressure on landfills, an environmentally friendly process. The outcome of these researches has remained on shelves and have not been harnessed to develop a footprint for its commercial application in construction. This review seeks to address this problem. Of the agricultural wastes studied, pozzolans from rice husk, palm oil wastes can be harnessed locally for processing and local utilization in locations unique to their generation source. Wastes from coconut shells and sugar cane are not viable in their current quantity to explore commercially. The waste from corn-cob and clay processed to pozzolana in concrete applications is commercially viable to meet the Nigerian demand. However, the cement manufacturing companies in Nigeria need to adopt these wastes to produce the cheaper corresponding blended cement alongside their regular cement. The Nigerian populace needs to be educated on the benefits of utilizing these pozzolans for ease of patronage

Progress From Selection of Some Maize Cultivars' Response to Drought in the Derived Savanna of Nigeria

Field experiments were conducted to investigate the variations in sixteen maize genotypes in relation to drought tolerance. The experimental set up was subjected to drought stress after five weeks of planting for three weeks before data on morphological and yield characters of maize genotypes were [DBO1] obtained for three cropping years. Plant height and grain yield of Bodija yellow maize were the highest overall. There was a significant difference among genotypes for drought stress resistance and Bodija yellow maize showed the most tolerance, while TZBR Comp 1 – C1 S2 510 genotype was the least. First principal component axis (Prin 1) had the highest contribution to the variation of the morphological, yield and drought tolerance traits. Prin 1 was highly related to the morphological and yield characters more than to the drought resistance. [U2] Plant height was negatively and strongly correlated (p<0.01) with stem height, number of leaves, stem girth, leaf length, leaf width and week after planting, but negatively correlated with the drought resistance. Therefore, Bodija yellow maize should be considered as parent material in breeding for the development of drought tolerant traits in maize

Pulverized Calcined Clay and Carbide Waste as Alternative Binder in Concrete and Mortar Applications for Sustainable Construction

Portland cement (PC) based concrete is the world’s most consumed man-made material and this consequently puts lots of demand on cement as a binder. The CO2 gas emission during cement clinker production has placed this important material into non-environmental-friendly classification with quest for greener alternatives being on the rise. A recent study showed combination of Pulverized Calcined Clay (PCC) and Calcium Carbide Waste (CCW) as possible alternative for total PC replacement with resulting appreciable mortar strength but delayed setting times and lower strength than PC mortars. This paper reports on effects of PCC-CCW as alternative binder on strength properties of mortars. The mortar mixes had superplasticizers added to reduce water/binder ratio while the CCW was treated to reduce impurities with a view to improving the strength development and a bid to mitigate the observed setbacks of earlier study. The pozzolanic activity indices of the PCC was determined via X-Ray Fluorescence(XRF) and strength determination (strength activity index). The PCC was combined with Purified CCW to determine the binder’s strengths at varying PCC:CCW replacements to determine the prescribed mix combination for optimum strength. Improved optimised mortar strength of 13.11MPa was achieved compared to 11.89MPa in the previous stud

Influence of Curing Age and Mix Composition on Compressive Strength of Volcanic Ash Blended Cement Laterized Concrete

Abstract: This study investigates the influence of curing age and mix proportions on the compressive strength of volcanic ash (VA) blended cement laterized concrete. A total of 288 cubes of 100mm dimensions were cast and cured in water for 3, 7, 28, 56, 90 and 120 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively while a control mix of 28-day target strength of 25N/mm 2 (using British Method) was adopted. The results show that the compressive strength of the VA-blended cement laterized concrete increased with the increase in curing age but decreased as the VA and laterite (LAT) contents increased. The optimum replacement level was 20%LAT/20%VA. At this level the compressive strength increased with curing age at a decreasing rate beyond 28 days. The target compressive strength of 25N/mm 2 was achieved for this mixture at 90 days of curing. VA content and curing age was noted to have significant effect (α 0.5) on the compressive strength of the VA-blended cement laterized concrete

Response of Maize (Zea mays L.) Genotypes to Liquid Effluents from a Non-alcoholic Beverage Company in Ibadan, Nigeria

Aims: This study was conducted to investigate the effect of liquid effluents discharged from a non-alcoholic beverage company on the growth of maize genotypes. Study Design: The screenhouse experiment was laid out in complete randomised design. Place and Duration of Study: The experiment was conducted at the nursery farm of the Department of Botany, University of Ibadan, Nigeria, between January and February and repeated between March and April, 2018. Materials and Methods: Maize genotypes; TZM – 1439, TZM – 29, TZM – 1288 and TZM - 1165 were obtained from maize germplasm in IITA Ibadan while the liquid effluent was collected from a bottling company in Ibadan and diluted with sterile distilled water into four different concentrations (0, 80, 90 and 100%). The varying concentration levels were evaluated on each maize genotype. Effluent was applied in the soil of the respective treatment at 200ml /pot/ day starting from the 10th day after planting. Data gathered on plants’ growth characters were subjected to ANOVA α0.05. Results: Maize cultivars treated with effluents concentrations, especially at 100% level significantly (p < 0.05) resulted in increased plant height (31.17 and 28.67 cm), stem length (7.81 and 7.53 cm), leaf length (22.18 and 20.63 cm) and leaf number (3.72, 3.61%) compare to the control respectively. Among the maize genotypes evaluated, TZM–1439, TZM-29 and TZM–1288 showed the most significant (p<0.05) effect on all the growth characters measured. No significant correlation exists between the effluent concentrations and genotypes with the growth characters, while the eigen proportion ranged from Prin 1 (67.10%) to Prin 5 (2.22%). Conclusion: The effluent from non-alcoholic beverage company’s treated maize plants recorded better growth performances at higher concentrations compare to the control experiment and could be further investigated for use in irrigation farming towards sustainability in agriculture