Browsing by Author "Akinyemi B.A"

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Effect of microwave assisted alkali pretreatment and other pretreatment methods on some properties of bamboo fibre reinforced cement composites
(2020) Akinyemi B.A; Temidayo Omoniyi T.E; Onuzulike G.
This study investigated the effectiveness of microwave irradiation pre- treatment in combination with sodium hydroxide and other pretreatment methods on bamboo fiber cement composite characteristics. The materials used for this study include bamboo fibers, Portland cement, fine sand and calcium chloride. Microwave assisted sodium hydroxide (MT), sodium hydroxide alone (AA) and hot water (HT) treatments were used to pre-treat the bamboo fiber before its use in the cementitious composite. Mechanical tests were conducted after 7, 14 and 28 days while Fourier transformed Infrared spectroscopy (FTIR) with Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to characterize the composites. The use of microwave assisted alkali treatment is observed to have the best performance due to its more efficient role in improving fiber roughness, ductility and toughness in the cementitious composites.
Effect of moisture on thermal properties of acrylic polymer modified mortar reinforced with alkali treated bamboo fibres
(2018) Akinyemi B.A; Omoniyi T.E
In this study, bamboo fibres were used as reinforcement materials for acrylic emulsion polymer modified cement bonded concrete after treatment with 10% weight of NaoH solution at 23 _C for 24 h. Thermal conductivity, thermal resistance and thermal transmittance were studied and the effects of moisture penetration at 11% wet basis were evaluated. Moisture penetration greatly reduced the thermal strength of the concrete with the exception at 10% acrylic polymer addition and 1.5% bamboo fibre inclusion. Based on the findings it can be reported that bamboo fibres greatly improved the thermal performance of the composite building material while the inclusion of acrylic polymers also hindered to a large extent the penetration of moisture into the capillary network.
Effect of moisture on thermal properties of acrylic polymer modified mortar reinforced with alkali treated bamboo fibres
(2018) Akinyemi B.A; Omoniyi T.E
In this study, bamboo fibres were used as reinforcement materials for acrylic emulsion polymer modified cement bonded concrete after treatment with 10% weight of NaoH solution at 23 _C for 24 h. Thermal conductivity, thermal resistance and thermal transmittance were studied and the effects of moisture penetration at 11% wet basis were evaluated. Moisture penetration greatly reduced the thermal strength of the concrete with the exception at 10% acrylic polymer addition and 1.5% bamboo fibre inclusion. Based on the findings it can be reported that bamboo fibres greatly improved the thermal performance of the composite building material while the inclusion of acrylic polymers also hindered to a large extent the penetration of moisture into the capillary network.
Repair and strengthening of bamboo reinforced acrylic polymer modified square concrete columns using ferrocement jackets
(2020) Akinyemi B.A; Omoniyi T.E
This study investigated the role of acrylic polymer as concrete matrix modifier and fer- rocement jacket confinement to repair and strengthen treated bamboo reinforced square concrete columns. 30 concrete columns (CC) of 150 ×150 ×600mm were produced us- ing cement:sand:aggregate ratio of 1:3:3 and a polymer:cement ratio of 1:10 based on ACI 548.3R standard. 10 CCs’ were produced from both conventional and modified concrete which were tested until failure. Another 10 CCs’ from both concrete design mixes were preloaded at 25%, 50%, and 75% of ultimate load and thereafter repaired with ferrocement jacket and axially tested. The last 10 CCs’ were ferrocement jacketed before axial testing. Axial and lateral deflections were evaluated during the tests. The crack pattern and fail- ure modes of the columns were also considered. The highest average ultimate load was obtained from column with ferrocement and polymer addition at 60% increase in compar- ison with the control column. The least axial and lateral deflections were 93% and 72% which were from columns repaired with ferrocement material. The cracks in the interface and its propagation developed with sequential increment of load and new cracks started to form at zones closer to the upper face in contact with the machine. Bulging and peeling of mortars characterised the failure pattern of the CCs’. Acrylic polymer and ferrocement jacket repaired columns showed an improvement which came close to the strength of the unrepaired.