A study of Compressive Strength Characteristics of Laterite/sand Hollow Blocks

This paper presents the results of experimental investigations carried out on partial replacement of sand with laterite as it affects the compressive strength of sandcrete hollow blocks. Two mix proportions (1:6 and 1:8) were used with laterite content varying between 0 and 50% at 10% intervals. Hand and machine compaction methods were used. Curing was done by sprinkling water on the specimens. The results showed that for each mix proportion and compaction method, the compressive strength decreases with increase in laterite content. Machine compacted hollow sandcrete blocks made from mix ratio 1:6 and with up to 10% laterite content is found suitable and hence recommended for building construction having attained a 28-day compressive strength of 2.07N/mm2 as required by the Nigerian Standards

Influence of Construction Materials Supply Chain Network Structures and Strategies on Project Delivery in Obafemi Awolowo University, Ile-Ife, Nigeria

The selection of type of contract for specific materials supply chain has been identified as one of the factors affecting materials management; and also affecting the objectives of construction material supply chain network systems which are the minimization of procurement cost, enhancement of material delivery and quality improvement. However, the influence of supply chain network systems as being practiced in the Nigerian Construction Industry on project delivery has not been well researched into. Therefore, this study carried out a questionnaire survey to address the problem. In total, 60 questionnaires were administered to small contractors and material suppliers in the study area with a response rate of 100%. The data was analysed using percentage tables, relative importance index, linear regression and Pearson’s coefficient of correlation and determination. The findings revealed that the use of phone and personal interaction are the network systems employed by small contractors to relate with material suppliers as both systems ranked 1st and 2nd respectively.  The findings also revealed that suppliers and small contractors are not employing Information Technologies in their supply chain network, and that strategies employed by contractors to select suppliers have positive influence on cost, quality and schedule of projects. Keywords: Construction materials, Supply Chain Network, Supply chain

Constructability Concepts and Enhancement Capabilities of Construction Site Team Members in Obafemi Awolowo University, Ile-Ife, Nigeria

The application of constructability principles is as important as the principles themselves, and the construction site is where the application can be carried out. The integrated efforts required to improve constructability on construction sites can be derived from project members’ team work. Constructability is a team effort making it imperative to have the team collectively define constructability challenges, opportunities and solutions; owing to the need to share construction innovations within and across site team members. In spite of this, few researches have been done related to constructability enhancement at the construction stage by the construction site team members. To address this, a total of 60 questionnaire were administered to site team members on construction sites in Obafemi Awolowo University with a response rate of 70%. Percentage frequency was used together with Relative Importance Index (RII) to analyse the data that was collected. Findings show that respondents have practical knowledge of constructability concepts and are capable of implementing them on construction sites. Effective planning of access to site ranked 1st with RII of 0.929 among the technical capabilities of the respondents; and also the capabilities of site engineers and resident builders to keep progress and quality management records ranked 1st among their constructability enhancement capabilities. Keywords: Constructability, constructability concepts, constructability enhancement techniques