scholarly journals Impact of Curing Methods on the Porosity and Compressive Strength of Concrete

2021 ◽  
pp. 18-30
Author(s):  
Francis Kwesi Nsakwa Gabriel-Wettey ◽  
Kennedy Appiadu-Boakye ◽  
Firmin Anewuoh
Keyword(s):  
Compressive Strength ◽  
Plain Concrete ◽  
Plastic Sheet ◽  
Cement Ratio ◽  
Medium Range ◽  
Jute Sack ◽  
Curing Methods ◽  
Compressive Strength Of Concrete ◽  
Curing Method ◽  
The Impact

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.

Effect of Admixed Recycled Aggregate on Properties of Recycled Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 743-746
Author(s):  
Ya Jun Zhao ◽  
Ying Gao ◽  
Li Li He
Keyword(s):  
Compressive Strength ◽  
Design Method ◽  
Orthogonal Design ◽  
Plain Concrete ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Influence Of Water ◽  
The Impact

The mixture proportion of recycled concrete was discussed by orthogonal design method. The influence of water-cement ratio, recycled aggregate quantity on workability, cube compressive strength of recycled concrete was analyzed. The experimental results indicated that，Recycled concrete mix proportion design should consider the impact of the water absorption of recycled aggregate. Unit water amount of recycled concrete should be plain concrete unit water consumption and recycled aggregate additional amount of water. Sand ratio should increase in the corresponding ordinary aggregate concrete sand ratio on the basis of 1 to 3 percent. When the water-cement ratio is 0.36 and construction waste content of 40% slag content of 20%, 28d compressive strength of concrete is 48.1MPa, slightly higher than the reference concrete (48.0MPa).

scholarly journals Effect of Selected Curing Methods on Density and Compressive Strength of Concrete for Technological Self-Reliance

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Grace M Amusan ◽  
Monsuru O Popoola ◽  
Jelili O Shittu
Keyword(s):  
Compressive Strength ◽  
Construction Projects ◽  
Physical And Mechanical Properties ◽  
Sustainable Growth ◽  
Cement Ratio ◽  
Concrete Members ◽  
Self Reliance ◽  
Curing Methods ◽  
Compressive Strength Of Concrete ◽  
Curing Age

The quest to deliver construction projects within the shortest possible time handled many engineers to maneuver curing ages of concrete and this has been a major concern in construction industries due to associated failures of concrete members emanating from improper curing. This study therefore aimed at investigating the effect of different curing methods on density and compressive strength of concrete with a view to enhancing technological self-reliance of the nation. Concrete cube specimens (150 mm × 150 mm × 150 mm) were cast using mix ratio 1:2:4 with 0.5 water-cement ratio. The concrete specimens were cured for 28 days using open air, ponding, sprinkling and dry covering curing methods. The compressive strength and density were evaluated. The data were validated. The results showed that the compressive strength increases with increasing curing age. The respective compressive strength values obtained for ponding, sprinkling, dry covering and open air curing methods were 22.04, 20.48, 17.28 and 16.02 respectively. The curing methods have compressive strengths in the order Ponding < sprinkling < dry covering < open air. The results of the curing methods on density were also noticed to be directly proportional to strength. Appropriate curing methods of concrete had greater impact in influencing physical and mechanical properties of concrete.Keywords: Concrete, Curing methods, Strength, Sustainable growth

scholarly journals Compressive Strength of Concrete Using Different Curing Methods

2020 ◽  
Vol 10 (3(S)) ◽  
pp. 30-38
Author(s):  
Daniel Yaw Osei ◽  
Zakari Mustapha ◽  
Mohammed D.H. Zebilila
Keyword(s):  
Compressive Strength ◽  
Structural Elements ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Curing Methods ◽  
Compressive Strength Of Concrete ◽  
Concrete Materials ◽  
Covering Method

The structural use of concrete depends largely on its strength, especially compressive strength.Various tests were carried out to ascertain the properties of concrete materials, whereas test performances ofthe concrete with different mix ratios at specific ages of curing were undertaken. The study determined thecompressive strength of concrete using different curing methods. Four different methods of curing (ponding,continuous wetting, open-air curing and sprinkling with water) were used. Seventy-two (72) cubes were castusing a mix ratio of 1:2:4 and 1:3:6 with 0.5 water cement ratio and with 0.6 waters cement ratio respectively.The compressive strengths were determined after 7 days, 14 days and at 28 days of curing. Findings showthat for 1:2:4 concrete, maximum of 28-day compressive was the highest for concrete cured by ponding andthe least was by sprinkling water. Further findings show that for 1:3:6 concrete, maximum of 28-daycompressive strength was obtained using ponding and the least was open air curing. Despite ponding methodproducing the highest compressive strength of concrete, it is practically impossible to cure cubes aboveground structural elements. Wet-covering method is recommended for structural elements, such as columns,beams and slabs in other to produce concreteof a required compressive strength.

scholarly journals Towards Sustainable Concrete Composites through Waste Valorisation of Plastic Food Trays as Low-Cost Fibrous Materials

2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir
Keyword(s):  
Compressive Strength ◽  
Low Cost ◽  
Impact Resistance ◽  
Food Tray ◽  
World Population ◽  
Fibrous Materials ◽  
Palm Oil Fuel Ash ◽  
Waste Plastic ◽  
Compressive Strength Of Concrete ◽  
The Impact

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.

Experimental Study on Sand and Cement Replacement by Termite Mound Soil

2019 ◽  
pp. 279-287
Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Compressive Strength ◽  
Natural Environment ◽  
Fine Aggregate ◽  
Test Results ◽  
Termite Mound ◽  
Cement Concrete ◽  
Cement Ratio ◽  
Compressive Strength Of Concrete

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.

scholarly journals Effect of Water Cement Ratios on Compressive Strength of Palm Kernel Shell Concrete

2019 ◽  
Vol 2 (Issue 1) ◽  
Author(s):  
A.O Adeyemi ◽  
M.A Anifowose ◽  
I.O Amototo ◽  
S.A Adebara ◽  
M.Y Olawuyi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Palm Kernel ◽  
Hardened Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Palm Kernel Shell ◽  
Compressive Strength Of Concrete ◽  
Palm Kernel Shells

This study examined the effect of varying water cement ratio on the compressive strength of concrete produced using palm kernel shell (PKS) as coarse aggregate at different replacement levels. The replacement levels of coarse aggregate with palm kernel shells (PKS) were 0%, 25%, 50%, and 100% respectively. PKS concrete cubes (144 specimens) of sizes 150mm x 150mm x 150mm were cast and cured in water for 7, 14, 21 and 28 days respectively. A mix ratio of 1:2:4 was adopted with water-cement ratio of 0.45, 0.5, and 0.6 respectively while the batching was done by weight. Slump test was conducted on fresh concrete while compressive strength test was carried out on the hardened concrete cubes using a compression testing machine of 2000kN capacity. The result of tests on fresh concrete shows that the slump height of 0.45 water cement ratio (w/c) increases with an increase in PKS%. This trend was similar to 0.50 and 0.60 w/c. However, the compressive strength of concrete cube decreases with an increase in w/c (from 0.45 to 0.60) but increases with respect to curing age and also decreases with increase in PKS%. Concrete with 0.45 water-cement ratio possess the highest compressive strength. It was observed that PKS is not a good substitute for coarse aggregate in mix ratio 1:2:4 for concrete productions. Hence, the study suggest the use of chemical admixture such as superplasticizer or calcium chloride in order to improve the strength of palm kernel shells-concrete.

scholarly journals Data on mixing and curing methods effects on the compressive strength of concrete

Data in Brief ◽  
2018 ◽  
Vol 18 ◽  
pp. 877-881
Author(s):  
Ignatius O. Omuh ◽  
Timothy O. Mosaku ◽  
Opeyemi Joshua ◽  
Rapheal A. Ojelabi ◽  
Lekan M. Amusan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Curing Methods ◽  
Compressive Strength Of Concrete

scholarly journals Impact of Temperature on the Strength Development of the Tailing-Waste Rock Backfill of a Gold Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Bin Han ◽  
Shengyou Zhang ◽  
Wei Sun
Keyword(s):  
Compressive Strength ◽  
Mass Concentration ◽  
Critical Concentration ◽  
Curing Temperature ◽  
Strength Development ◽  
Gold Mine ◽  
Critical Interval ◽  
Cement Ratio ◽  
Rate Of Increase ◽  
The Impact

This study investigated the influencing rules of curing temperature (5, 10, 16, and 20°C), cement ratio (8%, 10%, 12%, and 14%), and mass concentration (70%, 73%, 74%, and 75%) on the strength of backfill. In addition, a scanning electron microscope (SEM) is employed to analyze the microtopography of the backfill. Experimental results indicate that the uniaxial compressive strength (UCS) of the backfill decreases as the curing temperature diminishes; temperature substantially influences the earlier strength of backfill (it is much significant below 10°C). In addition, as the cement ratio rises, the critical point for the impact of temperature on strength gradually moves toward a low-temperature zone; in pace with the slurry mass concentration increase, the compressive strength of the backfill also rises and its rate of increase enlarges after going beyond the critical concentration. In case the curing temperature is lower than 10°C, the extent of hydration is also low inside the backfill. Through experiments, the critical concentration of slurry in the Jinying gold mine is determined as 73%, and the critical interval of the cement ratio ranged between 10% and 12%. Corresponding measures can be taken to increase the strength of backfill in the Jinying Gold Mine by 129.9%. As a result, backfill collapse is effectively controlled.

Mechanical Properties of Polypropylene Fiber Concrete after High Temperature

2014 ◽  
Vol 662 ◽  
pp. 24-28 ◽  
Author(s):  
Xi Du ◽  
You Liang Chen ◽  
Yu Chen Li ◽  
Da Xiang Nie ◽  
Ji Huang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Concrete ◽  
Compressive Strength Of Concrete ◽  
Polypropylene Fiber Reinforced Concrete

With cooling tests on polypropylene fiber reinforced concrete and plain concrete that were initially subjected to different heating temperatures, the change of mechanical properties including mass loss, uniaxial compressive strength and microstructure were analyzed. The results show that the compressive strength of concrete tend to decrease with an increase in temperature. After experiencing high temperatures, the internal fibers of the polypropylene fiber reinforced concrete melted and left a large number of voids in it, thereby deteriorating the mechanical properties of concrete.

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