Browsing by Author "Adeniji, Akintayo A."

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    Crack Mechanism of Different Concrete Grades under Compressive Loading: Application in Rigid Pavement
    (FUOYE Journal of Engineering and Technology, 2017-03-31) Oyedepo, Joseph O.; Dada, Temitope; Aladegboye, Segun; Adeniji, Akintayo A.
    The growth of cracks in concretes under different loadings in various structures and their consequent diminishing effect on the lifespan of structures is an age long structural problem. This research investigates the influence of compressive loading on the crack mechanism of different concrete grades 1: 1 : 3 (M20), 1: 2: 4 (M15) and 1: 3: 6 (M10) using three brands of cements available in Nigeria namely Dangote (Type A), Elephant (Type B) and Bua (Type C). Particle Size Distribution (PSD), Aggregate Crushing Value (ACV), Aggregate Impact Value (AIV) was carried out on aggregates in accordance with relevant codes while; compressive test were performed on the hardened concrete while, the crack width was measured using microscopic technique. A coefficient of uniformity (Cu) of 4.00, AIV of 46 % and an ACV of 47.7 % were obtained for the aggregate which are suitable for rigid pavements construction. Maximum compressive strength value of 24.96 N/mm2 , 24.67 N/mm2 and 24.89 N/mm2 respectively was obtained for concrete M20 for Type A, Type B and Type C cement at the 28 day. A corresponding crack width of 0.97 mm, 0.89 mm and 0.93 mm was obtained while; a yield period of 57.66 sec, 58.33 sec and 53.33 was obtained respectively. Comparing with the International Organization for Standardization, concrete grade M20 any of the cement types is suitable for the construction of rigid pavements with heavy traffic volume while M15 is recommended for low traffic volume.
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    Quality assessment of Sandcrete blocks in Ibadan – A review
    (Epistemics in Science Engineering and Technology, 2013) Adeniji, Akintayo A.; Ganiyu, A. A.; Ajagbe, W. O.
    Sandcrete blocks have been widely used for modern building construction in Nigeria; however cases of incessant building collapse are rampant. The usage of substandard sandcrete blocks is a contributing factor. This research was carried out to assess the engineering properties of sandcrete blocks produced in Ibadan and its environs. Two blocks each of size 450 x 225 x 225mm were purchased from selected block industries at eight sampled locations within the study area. Few units of blocks (450 x 225 x 225mm) conforming to the Nigerian Industrial Standard (NIS 87: 2007) were also produced to serve as control samples. The 28th day dry compressive strength test result obtained for the sampled blocks ranges between 0.39-2.34 N/mm2. For the control block samples, the average 28th day dry compressive strength of the three tested blocks was 3.02 N/mm2. Conclusively, it was observed that the sandcrete blocks produced in major parts of Ibadan were of low quality and substandard; while the control samples were of adequate strength.