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Effects of Capillary Rise Saturation on Properties of Sub Grade Soil
Issue:
Volume 5, Issue 2, December 2021
Pages:
32-49
Received:
30 November 2020
Accepted:
5 July 2021
Published:
10 July 2021
Abstract: Design of the pavement layer to be laid over the subgrade soil can start with the estimation of subgrade strength or capacity and the volume of traffic to be carried. Various pavement layers are very much dependent on the strength of subgrade soil over which they are going to be laid. The subgrade soil can be subjected to change in moisture or saturation level due to capillary rise/saturation (hc). The hydraulic conductivity of subgrade soil can be strongly dependent on the texture (contents), grain size, densities and voids of the soil. Change in moisture level in subgrade soil causes change in subgrade properties, strength or capacity and it can be quite essential for engineers to understand the effects of capillary rise on the variation of moisture in subgrade soil and effects on the strength properties. The strength properties of subgrade soil is mostly expressed in terms of CBR (California Bearing Ratio) and understanding the dependence of the CBR strength of subgrade soil on water content (moisture variation) will contribute better towards the design and maintenance practices. The strength of subgrade soil may vary largely on the amount of saturation in it, i.e. the amount of water exposed in the subgrade soil. Hence in this research an attempt has been made are to determine or estimate hydraulic conductivity of the subgrade soil at varies densities, Saturation level due to capillary rise/height at varies degree of soaking (time of saturation) from day (0) to day (4) and study the effects of capillary saturation on the properties of subgrade soil, including CBR at different level of saturation through the purposive sampling in each five stations. It observed that for each four stations subgrade soils, the strength properties reduced, i.e. the CBR values reduced from the un soaked condition to soaked condition. For sample 1 subgrade soils, the CBR values reduced by 82% to the un soaked condition or no change in moisture and provide a subgrade soil with non-susceptible to hydraulic conductivity which can reduces flow of water through them.
Abstract: Design of the pavement layer to be laid over the subgrade soil can start with the estimation of subgrade strength or capacity and the volume of traffic to be carried. Various pavement layers are very much dependent on the strength of subgrade soil over which they are going to be laid. The subgrade soil can be subjected to change in moisture or satu...
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Assessment of Awareness of Architects on Sustainable Building Materials in Minna, Nigeria
Ibrahim Adamu Umar,
Jonam Jacob Lembi,
Lilian Chioma Emechebe
Issue:
Volume 5, Issue 2, December 2021
Pages:
50-56
Received:
4 July 2021
Accepted:
9 July 2021
Published:
27 July 2021
Abstract: Sustainability is so important that both the MDGs and SDGs as United Nations development initiatives have listed it as a vital component. Non-sustainable practices lead to depletion and destruction of the environment with consequences that are still being understood. This could even get worst if professionals in the Building industry do not key into the sustainability initiative. Architects, as professionals in the built environment, take the most important decisions as far as the design and construction of buildings are concerned. Their awareness and knowledge of sustainable building materials is very important in solving this emerging problem. This study is aimed at evaluating the level of awareness of Architects on sustainable Building Materials. This is measured by looking at the knowledge, specification and application of sustainable building materials. The study was qualitative hence; data was obtained through a six-item structured schedule of interview. A total of 18 registered Architects were purposively selected for the study. The results obtained showed that as we get close to two decades since international attention has been drawn to sustainability, there is still a low level of awareness and knowledge of sustainable building materials among Architects. The study also revealed that Architects sometimes do not like pushing boundaries out of their comfort zones as far as specification writing is involved. In conclusion, the study recommended the updating of building bye-laws of the state, intending to make the Architects update their knowledge of sustainable Building Materials as a result of the more regular application in their designs.
Abstract: Sustainability is so important that both the MDGs and SDGs as United Nations development initiatives have listed it as a vital component. Non-sustainable practices lead to depletion and destruction of the environment with consequences that are still being understood. This could even get worst if professionals in the Building industry do not key int...
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Determination of Passenger Car Unit for Urban Roads: A Case Study in Addis Ababa
Helen Hordofa Tullu,
Emer Tucay Quezon
Issue:
Volume 5, Issue 2, December 2021
Pages:
57-63
Received:
8 June 2020
Accepted:
15 June 2021
Published:
6 September 2021
Abstract: In Ethiopia, specifically on Addis Ababa city roads operating, vehicles are mixed with varying static and dynamic traffic characteristics that are very challenging for the traffic analyst to come up with a sole solution to the traffic malady. Under heterogeneous traffic, each vehicle type cannot be compared with other vehicle types since it shows different effects on the road. It could be observed that the majority of the drivers in Addis Ababa road networks do not follow proper lane discipline to use any available space on the road sections. Currently, Ethiopia is using the passenger car unit values from other countries manual, which doesn't represent the local traffic and roadway conditions. This study was initiated to establish the PCU values that will cater the local settings. Hence, this study was focused on estimating the PCU values of multilane highways in Addis Ababa city and determining the influence of traffic volume and width of the road on the values of PCU. The PCUs were estimated for four vehicle types based on the variation of traffic volume and carriageway width. Dynamic PCU method was used to determine PCU values, and a linear regression analysis was performed for model development. The developed model is used to estimate PCU values having the same traffic conditions and roadway conditions found in other countries. The study results indicated that as the traffic volume and carriageway width increases, the passenger car unit value also increases. Also, it was found out that the results of PCU values in this study showed higher values than those provided in Highway Capacity Manual (HCM). Hence, the PCU values obtained are recommended to reflect the existing traffic condition in the locality.
Abstract: In Ethiopia, specifically on Addis Ababa city roads operating, vehicles are mixed with varying static and dynamic traffic characteristics that are very challenging for the traffic analyst to come up with a sole solution to the traffic malady. Under heterogeneous traffic, each vehicle type cannot be compared with other vehicle types since it shows d...
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The Study Bending Performance of Concrete Beam Using Bamboo Reinforcement and Fibres
Andi Yusra,
Teuku Budi Aulia,
Triwulan Triwulan,
Lissa Opirina,
Meylis Safriani
Issue:
Volume 5, Issue 2, December 2021
Pages:
64-72
Received:
7 November 2021
Accepted:
24 November 2021
Published:
29 November 2021
Abstract: The development of research on concrete used natural fibers has been conducted by many previous researchers. Where the fiber added to the concrete mix significantly increases the tensile strength of the concrete. In this study, natural fiber namely bamboo fiber, was used as micro reinforcement to strengthen the tensle strength of concrete. This study was conducted to determine how much strength bamboo is as the reinforcement as compared to steel reinforcement applied to high-performance concrete beams. It had expected that bamboo could be used as an alternative reiforcement to replace steel reinforcement in reinforced concrete bems. The study used four of beam specimen with dimension 150 × 300 × 2200 mm. The strength of Concrete is 60 Mega Pascal. The steel of tensile using four steel bars D16, while the steel of shear using two D12, and bamboo reinforced used 10 x 21 mm. The results shows maximum Deformation in concrete beams (HSC-SR) is 18.470 mm with the maximum loading 254.97 Kilonewtons, with ductility value is 1.713. The beams (HSC-SRBF) obtained Deformation10.260 mm at maximum load 264.78 Kilonewtons, and ductility is 1.832 mm. While the bamboo reinforced concrete beams (HSC-BR) obtained the maximum load is 106.89 Kilonewtons with Deformation is 28.700 mm, and ductility is 1.322, compare to beams (HSC-BRBF) obtained Deformation 24.440 mm at maximum load 158.87 Kilonewtons, with ductility is 1.162. The results give value of capacity beams for (HSC-BR) is 1.104, (HSC-SRBF) is 1.422, (HSC-SR) is 1.331 and (HSC-BRBF) is 0.877. In the beams (HSC-BRBF) use bamboo reinforced give the maximum load 158.87 Kilonewtons compare to (HSC-SRBF) have maximum load 254.97 KN.
Abstract: The development of research on concrete used natural fibers has been conducted by many previous researchers. Where the fiber added to the concrete mix significantly increases the tensile strength of the concrete. In this study, natural fiber namely bamboo fiber, was used as micro reinforcement to strengthen the tensle strength of concrete. This stu...
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