Effect of Curing Method and Final Moisture Condition on Compressive Strength of Concrete

1986 ◽  
Vol 83 (4) ◽  
2019 ◽  
Vol 136 ◽  
pp. 03009
Author(s):  
Yue Tian ◽  
Wanlai Zhang ◽  
Yihang Zhang

Based on the construction characteristics in the Northeast China Region under low temperature conditions, this article studies the influences of admixtures without antifreezing agent of different types and amounts on the low-temperature concrete and characteristics of pore structure. The results show that the amount of the admixtures is stable, the compressive strength of concrete under the curing condition of low temperature naturally varying is higher than the strength under the curing condition of constant low temperature while the porosity of the concrete under the curing condition of low temperature naturally varying is lower than the porosity under the curing condition of constant low temperature; The most appropriate curing method for the concrete used in winter construction is the curing method of low temperature naturally varying.


Author(s):  
Francis Kwesi Nsakwa Gabriel-Wettey ◽  
Kennedy Appiadu-Boakye ◽  
Firmin Anewuoh

An experimental investigation was conducted to evaluate the impact of different curing practices on the porosity and compressive strength of concrete. The targeted compressive strength of the concrete at 28-day of curing was 20 N/mm2. Plain concrete cubes were prepared with a mix ratio 1:1.5:3 by weight and 0.6 water-cement ratio. A total of 120 concrete cubes were tested on 7th, 14th, 21st, 28th and 56th day curing periods for slump, porosity and compressive strength. The four curing methods used were immersion, jute sack, plastic sheet and sprinkling which were all carried out in the laboratory under the same average environmental conditions of 27 ± 20°C temperature and 75% relative humidity. The results from the study showed that slump values were within the range of 52mm to 58mm which is within the medium range of 25 to 100mm, hence a true slump was achieved. The porosity of all samples decreased with age (i.e. at the dried state, immersion recorded the lowest 4.35%, followed by jute sack with 5.25%, plastic sheet 5.29% and sprinkling 5.55%). Again, the pattern of increases in concrete density (immersion curing produced concrete with the highest mean densities of 2369 kg/m3, jute 2360 kg/m3 ,plastic sheet 2277 kg/m3, sprinkling 2229 kg/m3 all for 56 days) was similar to that of the compressive strength (i.e immersion curing method yielded the highest compressive strength of 25.43 N/mm2, jute method 23.90 N/mm2, plastic method 23.47 N/mm2 , sprinkling method 22.33 N/mm2 for 56 days curing ages respectively). Therefore, increases in both compressive strength and densities of concrete cube is a function of curing method. The study concludes that the immersion curing method has the greater effect on the properties of concrete since it yielded the highest strengths. The recommendation is made for further studies on the impact of curing methods on the porosity and compressive strength of concrete on the field since this study was done in the laboratory under control conditions.


2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.


Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.


2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir

Recycling of waste plastics is an essential phase towards cleaner production and circular economy. Plastics in different forms, which are non-biodegradable polymers, have become an indispensable ingredient of human life. The rapid growth of the world population has led to increased demand for commodity plastics such as food packaging. Therefore, to avert environment pollution with plastic wastes, sufficient management to recycle this waste is vital. In this study, experimental investigations and statistical analysis were conducted to assess the feasibility of polypropylene type of waste plastic food tray (WPFT) as fibrous materials on the mechanical and impact resistance of concrete composites. The WPFT fibres with a length of 20 mm were used at dosages of 0–1% in two groups of concrete with 100% ordinary Portland cement (OPC) and 30% palm oil fuel ash (POFA) as partial cement replacement. The results revealed that WPFT fibres had an adverse effect on the workability and compressive strength of concrete mixes. Despite a slight reduction in compressive strength of concrete mixtures, tensile and flexural strengths significantly enhanced up to 25% with the addition of WPFT fibres. The impact resistance and energy absorption values of concrete specimens reinforced with 1% WPFT fibres were found to be about 7.5 times higher than those of plain concrete mix. The utilisation of waste plastic food trays in the production of concrete makes it low-cost and aids in decreasing waste discarding harms. The development of new construction materials using WPFT is significant to the environment and construction industry.


2021 ◽  
Vol 1107 (1) ◽  
pp. 012171
Author(s):  
A. C. Ekeleme ◽  
E. I. Ugwu ◽  
C.E. Njoku ◽  
E.C. Amanamba ◽  
E. E. Arinze ◽  
...  

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