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Ductile Evaluation and Mechanical Performance of Recycled Aggregate Concrete Using PVA and Steel Fibers
Chun Ho Kim,
Nam Wook Kim
Issue:
Volume 5, Issue 1, June 2021
Pages:
1-9
Received:
14 December 2020
Accepted:
28 December 2020
Published:
15 January 2021
Abstract: In recent years, a high toughness cement composite material (HTCCM) has been developed, which has far more performance than existing fiber reinforced concrete. HTCCM is a composite material made by reinforcing cement-based materials with fibers. It exhibits multiple crack characteristics under bending stress and greatly improves toughness during flexural, tensile, and compressive fracture. In this study, it is examined the mechanical properties of high fluidity and high toughness concrete (HFHTC) using fly ash as an admixture and recycled fine and coarse aggregate as an aggregate. From the standpoint of durability, it is necessary to fully examine the long-term properties of HFHTC using recycled fine and coarse aggregate, therefore, it is examined the strength and shrinkage of HFHTC using recycled fine and coarse aggregates.
Abstract: In recent years, a high toughness cement composite material (HTCCM) has been developed, which has far more performance than existing fiber reinforced concrete. HTCCM is a composite material made by reinforcing cement-based materials with fibers. It exhibits multiple crack characteristics under bending stress and greatly improves toughness during fl...
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Impact of Collaborative Processes on the Success of Construction Projects in Nigeria
Dorcas Titilayo Moyanga,
Charles Preye Adeoye
Issue:
Volume 5, Issue 1, June 2021
Pages:
10-14
Received:
4 February 2021
Accepted:
20 February 2021
Published:
29 April 2021
Abstract: Collaboration is essential to the success of construction projects and a defined collaborative process is one of the key elements of a successful relationship in construction. Although the consultant and contractor are key stakeholders in construction yet it is not being proven how their relationship affect projects in Nigeria’s construction industry. Therefore, this study evaluates the effect of collaboration on the success of construction projects. Quantitative study was conducted and primary data were collected through structured questionnaire on collaborative processes, success factors of projects in relation to collaboration and the impact of consultant-contractor collaboration on project success. The data collected from 135 consulting and construction firms in Lagos, Nigeria was analyzed using frequency distribution, mean score, ANOVA and multiple regression. The finding of the study revealed that the consultants and contractors are involved in the collaboration processes though they are mostly involved clear roles and responsibility, information sharing, cooperation and coordination, improved communication and collaborative governance. Also, the finding revealed that efficient coordination and dedicated team are the collaborative factors that contribute more to project success. Conclusively, the finding depicts that effective and efficient collaboration between consultant and contractor significantly impact the success of construction projects with R2 as 0.7403. The implication of the study is that project actors should continually accept and practice all levels and processes of collaboration and so as achieve a successful project delivery and pave way for the implementation of digital collaboration in Nigeria’s construction industry.
Abstract: Collaboration is essential to the success of construction projects and a defined collaborative process is one of the key elements of a successful relationship in construction. Although the consultant and contractor are key stakeholders in construction yet it is not being proven how their relationship affect projects in Nigeria’s construction indust...
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The Use of Yam Peel Ash as Partial Replacement of Cement Towards Achieving Low Cost Housing
Waheed Oyelola Balogun,
Oluwaseun Olatunji Otunola
Issue:
Volume 5, Issue 1, June 2021
Pages:
15-21
Received:
8 April 2021
Accepted:
21 April 2021
Published:
30 April 2021
Abstract: Yam Peels are the wastes produced when yam are processed for human consumption. This research investigated the structural strength characteristics of concrete with Yam peel ash (YPA) used as partial substitute for cement. The YPA was subjected to pozzolanicity and setting time tests to ascertain it potential as a pozzolan. Water/cement ratio of 0.6 was used to produce the blended concrete of mix 1:2:4, 1:3:6, 1:4:8 by which cement was replaced partially by YPA at 5%, 10%, 15% and 20% replacement by weight of cement. A total of 64 concrete cubes of size 50×50×50mm were molded and cured for 7, 14, 21 and 28 days. While 36 concrete beams of size 50×50×150mm were molded and cured for 7 and 28days. The workability, compressive strength and flexural test were conducted. The result revealed that the water/cement ratio is adequate to make the blended concrete workable. The best 28th day compressive strength of the blended concrete was observed for mix ratio of 1:3:6 at 5% YPA replacement of cement with a value of 9.857N/mm2, an approximate 64% of the strength of the concrete without replacement of cement. The best flexural strength of the concrete was observed at mix ratio of 1:2:4 at 5% YPA replacement with a value of 5.112N/mm2, an approximate 97% of the strength of the concrete without replacement of cement. The result further revealed that the increase in %YPA replacement of cement does not have any significant effect on the density of the test specimens of the blended concrete.
Abstract: Yam Peels are the wastes produced when yam are processed for human consumption. This research investigated the structural strength characteristics of concrete with Yam peel ash (YPA) used as partial substitute for cement. The YPA was subjected to pozzolanicity and setting time tests to ascertain it potential as a pozzolan. Water/cement ratio of 0.6...
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Improving Properties of Cinder Blended Materials for Construction of Low Volume Roads in Mbeya Region Tanzania
Duwa Hamisi Chengula,
Joseph Kilango Mnkeni
Issue:
Volume 5, Issue 1, June 2021
Pages:
22-31
Received:
5 June 2021
Accepted:
19 June 2021
Published:
25 June 2021
Abstract: The study to improve engineering properties of cinder blended materials was conducted in Mbeya region Tanzania. The low volume roads (LVRs) comprises of 75% of the whole road network and serves about 80% of population in Tanzania. The abundant materials in Mbeya region are cinders/scoria, pumices and volcanic soils which are originated from volcanic action. The samples from four source materials which are Ituha cinder, Ituha pozzolan, Mlimanyoka clay and Mbalizi gravel were collected for laboratory tests. Characterizations of source materials were conducted and grading coefficients (GC) and shrinkage products (SP) which are the requirements for selection of materials for surface layers of LVRs were computed. The results for GC and SP for all four source materials are out of range of 16 to 34 units and 100 to 365 units respectively. The California bearing ratios (CBR) at 95%MDD (maximum dry density) for four source materials are 17.6% for Ituha cinder, 25% for Ituha pozzolan, 3.2% for Mlimanyoka clay and 5.1% for Mbalizi gravel. The results for GC, SP and CBR for all four source materials indicated that the materials are not suitable for construction of surface layers of LVRs. The four source materials were blended together to get six blended sample materials targeting GC and SP ranges. The results of CBR values at 95%MDD for the six blended samples are 28% for 10MNCl40ITPo50ITCi0MBGr, 43% for 11MNCl40ITPo39ITCi10MBGr, 56% for 12MNCl35ITPo40ITCi13MBGr, 44% for 13MNCl32ITPo35ITCi20MBG, 39% for 14MNCl42ITPo44ITCi0MBGr and 53% for 15MNCl25ITPo35ITCi25MBGr. The improvement of CBR values of the six blended sample is because of enhanced interlocking and friction properties of the mixtures and addition of clay which act as binder to the coarse grain particles. It is important to develop suitable envelopes for surfacing layer materials of LVRs since interlocking and friction resistance are enhanced by gradation characteristics of material grain particles. For easy blending process of materials, an equation have been developed which can be used to blend materials using GC and SP parameters.
Abstract: The study to improve engineering properties of cinder blended materials was conducted in Mbeya region Tanzania. The low volume roads (LVRs) comprises of 75% of the whole road network and serves about 80% of population in Tanzania. The abundant materials in Mbeya region are cinders/scoria, pumices and volcanic soils which are originated from volcani...
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