Effects on the Surface Quality of Concrete According to the Changes in the Curing Methods and Compressive Strength
Issue:
Volume 7, Issue 6, December 2022
Pages:
102-108
Received:
20 October 2022
Accepted:
10 November 2022
Published:
8 December 2022
DOI:
10.11648/j.jccee.20220706.11
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Abstract: The durability of concrete slabs is apt to be influenced by finishing methods and curing methods of concrete surface. Therefore, the finishing agent had better use in case of high strength concrete, the wet curing had better carry out on concrete surface. However, it is not obvious that when wet curing is started after finishing of concrete surface. In this study, the effects of the difference in finishing methods and curing methods on the surface properties of concrete were examined by surface tensile test, air permeability test, water absorption test and scaling test. As a result, use of the finishing agent was effective to improve the surface properties in high strength concrete. However, use of the finishing agent was ineffective in normal strength concrete. When wet curing was carried out, high strength concrete was more effective than normal strength concrete. The surface properties of concrete could be improved when the wet curing was begun after it passed for several hours from finale set of the setting time test for concrete. It is considered that, however, there is not much difference in surface quality within that range, and it is acceptable to start curing water the next day.
Abstract: The durability of concrete slabs is apt to be influenced by finishing methods and curing methods of concrete surface. Therefore, the finishing agent had better use in case of high strength concrete, the wet curing had better carry out on concrete surface. However, it is not obvious that when wet curing is started after finishing of concrete surface...
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Research on Rapid Construction Technology of Changsha Shelter Hospital Based on Ontainer-Mold Combination
Chen Zhaorong,
Liao Fei,
Lv Jiping,
Ke Biaozhi,
Chen Hongtao,
Zeng Changluo
Issue:
Volume 7, Issue 6, December 2022
Pages:
109-117
Received:
29 November 2022
Accepted:
26 December 2022
Published:
29 December 2022
DOI:
10.11648/j.jccee.20220706.12
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Abstract: Natural disasters, especially serious infectious diseases, have brought a very heavy disaster to mankind. The outbreak of novel coronavirus pneumonia at the end of 2019 has spread to many countries around the world. As COVID-19 is spreading faster, more insidious and more contagious, the medical Administration of the National Health Commission pointed out in a press conference on March 22, 2022 that the Integrated Group of the Joint Prevention and Control Mechanism of The State Council require each province to have at least two to three shelter hospitals. Combining with the main rapid construction technology adopted in the construction of shelter hospital, this paper puts forward the design concept of "container-mold combination". Parallel construction is adopted to facilitate the coordination of resources and ensure the maximization of construction progress. The main process of rapid construction technology is introduced, which mainly includes sample road guide, subcontractor approach, work face handover, coordination of public service units, and final stage. The construction deployment of anti-epidemic medical buildings and supporting rapid construction technology is summarized, and the deployment principle, construction organization, construction deployment and professional task arrangement are emphasized. The speed target of completing the drawing design in 24 hours, constructing the temporary facilities in 36 hours, and pouring the first bottom plate in 5 days was achieved, with a total of 28 days to complete the shelter hospital.
Abstract: Natural disasters, especially serious infectious diseases, have brought a very heavy disaster to mankind. The outbreak of novel coronavirus pneumonia at the end of 2019 has spread to many countries around the world. As COVID-19 is spreading faster, more insidious and more contagious, the medical Administration of the National Health Commission poin...
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Assessment of Pozzolanic Reaction and Resulting Strength of Dune Sand Stabilized with Cement Supplementary Pozzolanic Waste Materials
Sandipkumar Kori,
Manish Shah
Issue:
Volume 7, Issue 6, December 2022
Pages:
118-124
Received:
24 May 2022
Accepted:
8 June 2022
Published:
29 December 2022
DOI:
10.11648/j.jccee.20220706.13
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Abstract: Sand dunes are formed due to the earth’s erosional and depositional forces. Dune sand being collapsible and due to lose formation, is not suitable to be used as subgrade material for pavements or any other infrastructure applications as its sand grains contain large voids in between which results in its poor gradation and inability of being compacted. The prime objective of this research paper is to estimate the feasibility of using and converting dune sand into sustainable fill material and improving its engineering characteristics as well as its gradation using pozzolanic cement supplementary wastes in optimum proportion. To achieve this objective three types of pozzolanic wastes viz. Wheat straw ash (WSA), Fluid catalytic cracking catalyst residue (FC3R), Nano silica (NS) were used replacing cement partially in proportion of 2%, 3%, 4% and 5% respectively aggregating total additives (waste + cement) as 8%, 10%, 12% and 14%. The engineering parameters MDD, OMC, UCS and CBR are mainly evaluated from this study. From the results and analysis, it is observed that partial replacement of 2% WSA, 14%FC3R and 3%NS showed the maximum improvement in UCS values. Further the results obtained for various percentage of dosages were compared with recommendations given by IRC for cement stabilization.
Abstract: Sand dunes are formed due to the earth’s erosional and depositional forces. Dune sand being collapsible and due to lose formation, is not suitable to be used as subgrade material for pavements or any other infrastructure applications as its sand grains contain large voids in between which results in its poor gradation and inability of being compact...
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