Review of Sustainability in Self Compacting Concrete: the use of waste and mineral additives as supplementary cementitious material and aggregate.

Concrete is one of the commonly used construction materials, but there is a need to develop a new and sustainable technology to make concrete more affordable. With the advancement in technology, concrete was no longer seen as a three entity (binder, aggregate, and water). The unique workability properties of SCC make it unique in the concrete industry. This review assessed the materials, strength, rheological properties of agricultural waste, industrial waste and mineral additives in SCC production. The effect of the utilization of these additives and replacements on structural, mechanical and rheological properties of SCC was espoused. The review revealed that the use of both industrial and agricultural waste enhances the strength properties of SCC. Additionally, the use of agricultural waste improves the rheological properties of fresh concrete. The utilization of expansive material should be discouraged in SCC production. The review revealed that SCC developments ensure a good balance between deformability and stability. It was therefore recommended that SCC should be utilized in pavement construction, particularly when high axle load is expected

Travel Behaviour Of University Enviroment: Inter-Relationship Between Trip Distance And Travel Mode Choice In South-Western Nigeria

Universities’ trip pattern is an important component of overall transportation demand of a province but it is often not well represented in travel demand models. This research assessed the spatial commuting patterns of the three categories of universities in Southwestern Nigeria. This was achieved with the uniform distribution of 3000 questionnaires with 80% return rate using face to face approach. Statistical software was employed in the analysis of the data. Distance was found to be a function of commuting pattern as it has a coefficient of determination (R2) value of o.64. Moreover, 81% and 65% of staff in private and government owned universities respectively adopted the use of private cars, while walking and the use of shuttle buses were predominantly used by students for both long and short trip distances. The study showed that the use of shuttle is not affected by trip distance as compared to the other modes. However, cycling and walking should be encouraged to minimize the overdependence on the use of shuttle for both short and long distance trips. In addition, emission of greenhouse gases in universities’ environments in Nigeria could be reduced if adopte

PERFORMANCE OF STEEL SLAG AGGREGATE CONCRETE WITH VARIED WATER- CEMENT RATIO

Several thousands of tons of electric arc furnace slag (EAF) slag generated in Nigeria are yet to be utilised for construction; perhaps as a result of inadequate technical details for its use. The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively. SSA was substituted in increments of 20% by weight of granite until 100% mix, while w/c was varied at 0.5, 0.55 and 0.6. Workability of fresh concrete was evaluated through slump test. Hardened concrete cubes and cylinders were subjected to compression and split tensile tests respectively, after 7, 14 and 28 days curing periods. Slump values obtained were in the range of 50 – 90 mm for all the mixes, which represented a S2 slump. Compressive strength and tensile strength increased with age and increasing slag substitution. A strength of 25 MPa for normal weight concrete was achieved at 28 days with 20% SSA substitution, only within 0.5 and 0.55 w/c ratio. However, result obtained for concrete mixes with 60% SSA and above at 28 days established that these mixes are good for production of high strength concrete