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Effects of Using 0.5, 0.55 and 0.6 Water Cement Ratio Separately With a Nigerian Grade 42.5R Portland Cement
Issue:
Volume 4, Issue 6, November 2016
Pages:
80-88
Received:
3 July 2016
Accepted:
11 July 2016
Published:
28 October 2016
DOI:
10.11648/j.ijsts.20160406.11
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Abstract: This research paper is for the purpose of disseminating the results of an investigation into the effect of water cement ratio of 0.5, 0.55 and 0.6 separately while producing most commonly practiced concrete of cement, fine aggregate and coarse by 1:2:4 mixtures. This research study is limited to the use of newly grade 42.5R Portland cement that is being produced in Nigeria recently and of which is readily available. River sand was used as fine aggregate and coarse aggregates used separately were washed gravel, 19 mm and 12.5 mm granites. Nine different concrete mixtures were produced and it is important to note that the results of their slump tests deviated considerably from that of the compacting factor tests correspondingly while considering the degree of workability values. Conducting this research the potential impact derived is that only the use of 19 mm granite with water cement ratio of 0.5 and 0.55 achieved at 28 day flexural strength concrete grade of 4.92 N/mm2 and 4.84 N/mm2 respectively whilst are marginally greater than the standard specification value of 4.5 N/mm2. The significance of this study is that while at when the flexural strength of concrete is satisfied the corresponding tensile strengths values which are 2.684 N/mm2 and 2.590 N/mm2 do not satisfy the required standard specification values which are respectively 3.355 N/mm2 and 3.238 N/mm2. The contribution to knowledge as regards to this research work is in the enlightenment benefit revealed upon the possible prevention of economic loss that can occur due to early rigid pavement failure for roads, petroleum filling station concrete pavements in cities and rural towns or yards for offices and factories due to design of poor concrete proportioning and the use of the new cement.
Abstract: This research paper is for the purpose of disseminating the results of an investigation into the effect of water cement ratio of 0.5, 0.55 and 0.6 separately while producing most commonly practiced concrete of cement, fine aggregate and coarse by 1:2:4 mixtures. This research study is limited to the use of newly grade 42.5R Portland cement that is ...
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Strength Characterization of Stabilized A-5(10), A-7-5(16), A-4(3) and A-2-7(1) Laterite Soils Individually Using Supaset Cement
Issue:
Volume 4, Issue 6, November 2016
Pages:
89-98
Received:
4 September 2016
Accepted:
13 September 2016
Published:
28 October 2016
DOI:
10.11648/j.ijsts.20160406.12
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Abstract: The purpose of this research work is on the strength characterization of the Supaset Portland cement stabilized with laterite soil materials from four different borrow pits locations within Southwest part of Nigeria and the level of their usefulness for highway pavement subbase and basecourse. The four laterite soils after laboratory experiments are classified as A-5(10) silty soil; A-7-5(16) clayey soil; A-4(3) silty soil and A-2-7(1) clayey gravely sandy soil respectively. Stabilization of each laterite soil with the cement at percentages of 0% through 14% at the interval of 2% shows that with the increase in cement content during stabilization process the optimum moisture content of each soil specimen is reducing while the related maximum dry density is increasing. Furthermore, while considering at natural and stabilized states, both unsoaked and soaked California Bearing Ratio, uncured and unconfined compression strengths values of the tested specimens are increasing with increase in cement content with soil A-4(3) having the highest value while soil A-5(10), A-2-7(1) and A-7-5(16) values followed respectively. The coefficient of permeability of each soil specimen stabilized was reducing as the cement content was increasing. The chemical composition tests on Supaset Portland cement revealed CaO and SiO2 are the major components while for those of soils are SiO2 and Al2O3. The significance of this study is that although A-5(10) and A-4(3) silty soils stabilized by Supaset Portland cement of grade 32.5R attained the 750 kN/m2 minimum standard strength requirement for subbase, A-7-5(16) and A-2-7(1) clayey soils did not satisfy same. The justification for this research is that Supaset Portland cement is an economical and valuable material to stabilize silty soils but not cost-effective for the stabilization of clayey soils for highway pavement in order to prevent its incessant and premature failure.
Abstract: The purpose of this research work is on the strength characterization of the Supaset Portland cement stabilized with laterite soil materials from four different borrow pits locations within Southwest part of Nigeria and the level of their usefulness for highway pavement subbase and basecourse. The four laterite soils after laboratory experiments ar...
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Fire Risk Analysis and Emergency Evacuation Study on Large Comprehensive Building
Issue:
Volume 4, Issue 6, November 2016
Pages:
99-105
Received:
13 October 2016
Accepted:
27 October 2016
Published:
11 November 2016
DOI:
10.11648/j.ijsts.20160406.13
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Abstract: To prevent and control the fire risk of large comprehensive building, taking Jianye shopping plaza as an example, with the analytic hierarchy process (AHP) to establish large comprehensive building fire risk evaluation index system, the final evaluation index and fire risk level of Jianye shopping plaza is calculated by using the security check points and weight of the cumulative.Crowd evacuation time is simulated by using FDS, which can conclude that, in the ideal state, emergency evacuation time is 150 s and 3500 people are evacuated completely. In actual running state investigation, however, it is concluded that researchers were completely evacuated after the 450 s, while only 1500 people have been evacuated in 150 s.Finally, trajectory intersection theory is put forward in two aspects of the fire risk and emergency evacuation measures. Suggestions and measurements are proposed in order to prevent fire in reality and improve the possibilities timely as well as effectively in crowd evacuation after the fire, which are able to guarantee the safety of people.
Abstract: To prevent and control the fire risk of large comprehensive building, taking Jianye shopping plaza as an example, with the analytic hierarchy process (AHP) to establish large comprehensive building fire risk evaluation index system, the final evaluation index and fire risk level of Jianye shopping plaza is calculated by using the security check poi...
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A Comprehensive Review of Current Applications of Artificial Neural Networks in E-Learning Environment
Rana Khudhair Abbas Ahmed
Issue:
Volume 4, Issue 6, November 2016
Pages:
106-109
Received:
8 December 2016
Accepted:
17 December 2016
Published:
14 January 2017
DOI:
10.11648/j.ijsts.20160406.14
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Abstract: With the rapid increase in the development of online learning technology and the huge amount of learning materials generated on the web. Besides, the learning resources are growing infinitely making it difficult for users to choose appropriate resources for their learning. This paper discusses current applications of artificial neural networks and its great potential to help users in a personal learning environment to identify relevant and interesting items from a large number of items by suggesting actions to learners.
Abstract: With the rapid increase in the development of online learning technology and the huge amount of learning materials generated on the web. Besides, the learning resources are growing infinitely making it difficult for users to choose appropriate resources for their learning. This paper discusses current applications of artificial neural networks and ...
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