Evaluation of the compressive strength of commercial sandcrete blocks produced in two metropolises of Delta State, Nigeria

The mechanical properties of sandcrete block greatly influenced the durability of structures built from it. This study was carried out to assess the compressive strength of sandcrete blocks produced in two major developmental and rapidly urbanizing zones of Delta State, Nigeria. 150 and 225 mm sandcrete blocks were sampled from 18 blocks moulding factories in Ndokwa East and Ughelli North Local Government Areas of Delta State, Nigeria. Five sandcrete block was sampled from each block moulding factory, at the rate of 9 factories per Local Government Area. The compressive strength of the sampled blocks was determined in accordance with the ASTM International standards. The results of compressive strength test showed that the compressive strengths of the blocks, regardless of the block size ranged from 0.61 to 16.19 MPa. Analysis of the results revealed that apart from the customized blocks, the compressive strengths of all the other blocks fell below the Nigerian Industrial Standard (NIS) recommendations of 2.5 MPa for non-load bearing walls. The general poor quality of the sandcrete blocks is attributed particularly to the poor mix ratios adopted by the block producers which fell short of NIS recommendations. Thus, this study recommended that standard regulatory agencies should closely monitor all the block making factories in the state, to ensure that sandcrete blocks produced or brought into the state met NIS recommendations

Design, development and performance evaluation of a smart office automation system

This research work aimed at the design, development and performance of Office Automation System, using the Internet of Things (IoT) based and Voice Recognition Command. The data is stored in personal computer (PC) or android smartphone. Arduino IDE was the framework used in the development of the system, while C++ was the programming language used for programming the system. Similarly, a voice control was built using the This Then That (IFTTT) platform. The system developed was capable of enabling users to control office appliances like printer, air conditioner, light, fan, etc. with voice command using the Google home mini device. Results obtained from the laboratory test proved that the system had a very high (about 98%) performance rating. This system had shown that office automation system can use voice command to preform its task

Evaluation of the impact of chemical admixtures on the compressive strength properties of concrete

This study was carried out to evaluate the effect of chemical admixtures on the compressive strength of concretes. The concretes were produced with the concrete mix ratio of 1:2:4, while water to cement (w/c) ratios of 0.35, 0.4, 0.45, 0.5 and 0.55 were adopted. Different concrete mixtures were produced using two chemical admixtures (hydroxycarboxylic acid and MasterRheobuild 1100) applied at the rate of 1.3% (weight of the cement), during the production process. Laboratory results of the fine aggregate used for the concrete production showed that it was well graded met international standards. All the concretes were produced and tested in accordance to American Society for Testing and Materials (ASTM) standard procedures. Results indicated that the concrete produced with the chemical admixtures showed better concrete performances both in the fresh and hardened state. After 28 days of casting, concrete produced with MasterRheobuild 1100 admixture had the best compressive strength (32 MPa); compared with the compressive strength of the concrete produced with the hydroxycarboxylic acid admixture (28 MPa), and the control concrete samples that had compressive strength of 25 MPa. In addition, the fresh concrete produced with chemical admixtures gave a better slump than the fresh concrete produced without any chemical admixture. Likewise, hydroxycarboxylic acid admixture performs better among the two admixtures used, given a more linear relationship between the slump and water/cement ratio. These results showed the importance of chemical admixtures when higher compressive strength becomes a vital factor in structural constructions

Evaluation of the mechanical properties of sawdust, oil bean pod filler, raffia palm fibre and CaCO3 filled/epoxy hybridized composite

This work was carried out to develop green composite from organic materials which are cheaply available within Nigeria. This study deals with the hybridization of epoxy composite with different organic materials. Five diffident composites were produced with the hybridization of matrix, sawdust (SD), raffia palm fibre (RPF), oil bean pod filler (OBPF) and calcium carbonate (CaCO3) mixed at different volume. The composite samples were produced through the hand layup method, and their tensile and flexural properties, determined in accordance to ASTM International procedures. Results obtained from the laboratory tests indicated that the reinforcement materials greatly influenced the mechanical properties of the composite samples. The result revealed that the hybrid composite of SD, CaCO3 and RPF had the best, compared to the other composite with different reinforcement materials. Similarly, it was observed that the composite produced with SD, OBPF and RPF had better tensile and flexural properties as compared to the composite reinforced with SD and CaCO3. This study affirmed that organic materials can be used to replace inorganic material (CaCO3), hence the actualization of green composite is practically feasible

Series of 1-D ER and IP traverses reveal vestige of regional geological structure

At the Basement Complex geological province of central Nigeria, in the state of Niger, just northeast of the Bida Sedimentary Basin, there is the character of non-complexity and high uniformity in the local geology over an appreciable linear spread. This appreciation makes it a standard practice to do one-dimensional vertical electrical sounding surveys in the search for groundwater resources at this area with the expectation of reliable results. This seeming “simplicity” means that intense manual labour can be invested in acquiring a large data-field at a local area of survey where resources are not readily available to do a standard two-dimensional survey of the conventional kind. This is especially significant for the proposed area of development at the Gidan Kwano Campus of the Federal University of Technology, Minna, Thus, with this awareness and the use of the ABEM Terrameter 4000 equipment, the aim of this study was to do an intense acquisition of one-dimensional electrical resistance and concomitant induced polarization programme for this proposed area of development so as to achieve the objective of garnering information about exploitable groundwater locations before structural developments cover these points up. Typical point-to-point one-dimensional tandem electrical resistance and concomitant induced polarisation surveys were completed along east-west profile lines for about 309 survey stations of the available 441 principal locations of the 4 km2 extent of the proposed new development. After due processing and interpretation of the data-field of this survey, whilst remarking that the induced polarisation data-set was used herein as quality control “refiner” only, clusters of reliable groundwater locations were observed at the southwest end of the 4 km2 areal extent of the proposed new development. It conforms to the dip of the landform and comparatively significant overburden-material thicknesses observed over there. Interestingly, in a twist of serendipity, the series of diagonal subsurface “fault-lines” that connect one promising groundwater prospect with the other, describable by a prominent northeast-southwest dip, aligns exactly with the Kazaure-Karaukarau-Kushaka-Ilesha Schist Belt. In the modern geography setting of the present time, the Kazaure-Karaukarau-Kushaka-Ilesha Schist Belt actually traverses a lengthy diagonal across the landscape of Nigeria, cutting through such Nigerian states as Jigawa, Kano, Kaduna, Niger, Kwara, Ekiti, and Osun. There is virtually no surface indicator of this once-prominent schist belt and what this study reveals is its vestigial signature

Performance evaluation of inter-cell interference prediction in massive MIMO

This paper presents inter-cell interference prediction in massive multiple input multiple output. The rapid demand for widespread multimedia services notwithstanding the deployment of 4G in Lagos, Nigeria and the urgent need to upgrade to 5G networks with downlink and uplink data capacities of not less than 300 and 60 Mbps, respectively for at least 95% penetration rate at any instantaneous time; there is a possibility of experiencing crosstalk and adjacent inter-cell interference within the receiving antennas. 5G inter-cell interference prediction scheme that employs LTE performance index using locally sourced data from Huawei Nigeria limited was presented. The performances of the currently deployed LTE network were evaluated by employing performance metrics such as uplink and downlink capacities and recommending a possible inter-cell interference mitigation technique to be implemented in the deployment of 5G network in Lagos. The identified key performance metrics used include over the air emulation, carrier to interference plus noise ratio, peak RLC throughput, coverage probability, and the map-based model. Hence, ICIC static coordination algorithm, which comprise NOICIC, Hard FFR, PFR, SFR and SFFR were analyzed. With static ICIC algorithm, the coverage probability was 78% for receiving more than 20 kbps, with cell-edge users using resources of centre-users and with edge-users of neighbouring cells using different resource block; therefore reducing interference and consequently increasing throughput when there is static ICIC coordination. Implementing the static ICIC schemes on the 5G network when deployed in Lagos will improve the average downlink throughput over what is currently attainable with the 4G network in use at the moment