This study compared the physical and mechanical properties of river sand concrete with quarry dust concrete. The constituent materials were batched by weight. The water-cement ratio and mix ratio selected for the experimental investigation were 0.55 and 1:2:4, respectively. The specimens were cured for 7, 14, 21 and 28 days. Slump, density and compressive strength tests were carried out. The results showed that river sand concrete had greater density and compressive strength than quarry dust concrete for all curing ages. At 28 days of curing, river sand concrete exceeded the target compressive strength by 36%, whereas quarry dust concrete was less than the target compressive strength by 12%. Both river sand concrete and quarry dust concrete for the selected water/cement ratio and mix ratio are suitable for non-structural applications and lightly-loaded members where high strength is not a prerequisite.

Purpose This paper aims to investigate the 28-day compressive strength of concrete produced with aggregates from different sources. Design/methodology/approach Coarse aggregates were crushed granite and natural local stones mined from Umunneochi, Lokpa and Uturu, Isuakwato, respectively, in Abia State, Nigeria. Fine aggregate (river sand) and another coarse aggregate (river stone) were dredged from Otammiri River in Owerri, Imo State, Nigeria. The nominal mix ratios were 1:1:2, 1:2:4 and 1:3:6, whereas the respective water–cement ratios were 0.45, 0.5, 0.55 and 0.6. Findings The compressive strength of granite concrete, river stone concrete and local stone concrete ranged 17.79-38.13, 15.37-34.57 and 14.17-31.96 N/mm2, respectively. Compressive strength was found to increase with decreasing water–cement ratio and increasing cement content. Practical implications Granite concrete should be used in reinforced-concrete construction, especially when a cube compressive strength of 30 N/mm2 or higher is required. Originality/value Granite concrete exceeded the target compressive strength for all the concrete specimens, whereas river stone concrete and local stone concrete failed to achieve the target strength for some mix proportions and water–cement ratios.

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Quality of concrete explains considerably the state of affairs involved in the production of concrete in a particular area. The antecedents of the production process to a greater extent therefore have a way of predicting the expected quality of a product. Hence, the degree of relationship between the quality of concrete and its production characteristics is determined in the study. Field work adopted in the study comprises activity sampling and ex post facto experimental designs. These two different research designs were applied to obtain data for performance assessment of activities involved in the production procedures and laboratory tests of concrete produced at various sites in the study area respectively. The corresponding data obtained in the field work are in ordinance and ratio scales of measurement. Regression analysis was used to establish a casual relationship between the two variables - performance level of the production characteristics (x) and the compressive strength (y) of the concrete at various sites in the study area. A model relationship of simple regression analysis for the dependent and independent variables is established. Finding reveals that the better the ranking of sites in compliance with the standard practice of production characteristics, the higher the compressive strength property of the concrete produced on site; hence the linear relationship. The coefficient of determination shows that 93% of changes in the strength property of concrete are caused by the production characteristics. Although the highest value of compressive strength obtained as 10.80 N/mm2 goes with the best state of affairs of the production characteristics in the study, it does not meet the minimum stipulated specification for the strength.  Hence, other critical factors such as; aggregate type, and mix design should be considered for desired quality of concrete in the study area. Besides, enforcement of uniformity in production process as standard practice by all the firms should as a matter of urgency be implemented formally by the government in the state for improved quality of concrete in general.