Workability and Compressive-strength Development of Volume-batched Site-mixed Concrete in Bahrain: Descriptive Comparison with Historical Ready-mix Data

Abstract

This study characterised the workability and compressive-strength development of two nominal volume-batched site-mixed concrete formulations, 1:2:3 and 1:2:4, prepared under reported experimental conditions in Bahrain, and contextualised their 28-day strengths using aggregated historical ready-mix data. One manually mixed batch was prepared per formulation using a 6 L batching unit and a nominal added-water–cement ratio of 0.50 by mass. Three slump determinations were conducted per batch, and twelve 100 mm cubes were produced per formulation, with three tested after 7, 14, 21 and 28 days of curing. Slump and compressive strength were determined in accordance with BS EN 12350-2 and BS EN 12390-3, respectively. Mean slump was 100 ± 0 mm for the 1:2:3 batch and 130 ± 0 mm for the 1:2:4 batch; both were classified as S3. Mean compressive strength increased from 32.53 MPa at 7 days to 39.63 MPa at 28 days for the 1:2:3 batch and from 24.53 to 28.20 MPa for the 1:2:4 batch. The 1:2:3 batch recorded the higher mean strength at every age. The historical ready-mix mean of 33.1 MPa lay between the two 28-day site-mixed means but was used only as descriptive context because essential testing details and individual observations were unavailable. With only one batch per formulation and no measured aggregate grading, moisture or absorption, the findings do not establish production reliability, concrete-class conformity, durability or structural suitability.