scholarly journals Study on Compressive Strength of Concrete Mixed with Various Types of Powder at Constant Cement Contents by Taking Account of Pore Structure

2013 ◽  
Vol 24 (3) ◽  
pp. 89-100 ◽  
Author(s):  
Hiroki Suyama ◽  
Tomoyuki Koyama ◽  
Korekiyo Ito ◽  
Yasunori Matsufuji
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Compressive Strength Of Concrete

scholarly journals The influences of admixtures on the characteristics of pore structure of low-temperature concrete under different curing conditions

2019 ◽  
Vol 136 ◽  
pp. 03009
Author(s):  
Yue Tian ◽  
Wanlai Zhang ◽  
Yihang Zhang
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
Pore Structure ◽  
Northeast China ◽  
Curing Conditions ◽  
Different Types ◽  
Compressive Strength Of Concrete ◽  
Curing Condition ◽  
Curing Method ◽  
China Region

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.

Physical Filling Effects of Limestone Powders with Different Particle Size

2010 ◽  
Vol 163-167 ◽  
pp. 1419-1424 ◽  
Author(s):  
Yu Li Wang ◽  
Wei Dong Wang ◽  
Xue Mao Guan
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Mineral Admixture ◽  
Limestone Powder ◽  
Cement Stone ◽  
Particle Sizes ◽  
Powder Mixtures ◽  
Mass Proportion ◽  
Void Structure ◽  
Compressive Strength Of Concrete

Physical filling effects of limestone powders, which are stated by compactness change of mixtures of limestone powders and cement, play an important role in the pore structure and strength of cement stone. The compactness of mixture of limestone powders and cement has been analyzed by the method of wet packing density, tested the void structure of cement stone by mercury intrusion porosimetry(MIP) and strength of cement stone. Effects of limestone powders with specific areas of individually 416m2/kg, 841m2/kg, 1243m2/kg on compactness of cement, compressive strength of concrete as mineral admixture, and pore structure of cement stone were studied when its cement is substituted for the mass proportion of 5, 10, 15% with it. The results show that the compactness of powder mixtures and compressive strength of concrete are biggest, and the improvement of pore structure of cement stone is the best when limestone powder is 10%; the compactness of powder mixtures and compressive strength of concrete are bigger, and the improvement of pore structure of cement stone is better when limestone powder is finer. That is to say, the proportion of limestone powder is the best substitution at 10%; physical filling effects of limestone powder are better when limestone powder is finer from particle sizes. It is important guiding meaning for the application of limestone powder in cement materials.

scholarly journals Influence of Reinforcement Bars on Concrete Pore Structure and Compressive Strength

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 658
Author(s):  
Jianmin Hua ◽  
Fengbin Zhou ◽  
Lepeng Huang ◽  
Zengshun Chen ◽  
Yemeng Xu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Pore Structure ◽  
Reinforcement Ratio ◽  
Concrete Compressive Strength ◽  
Gradual Reduction ◽  
Compressive Strength Of Concrete

In this research, the influence of reinforcement bars on concrete pore structure and compressive strength was experimentally investigated. Concrete samples with two mixture ratios and nine reinforcement ratios were provided. Tests were conducted on concrete pore structure and compressive strength at three ages (3 d, 7 d, and 28 d). It was found that reinforcement bars changed the concrete pore structure. In terms of size, the pore structure of concrete increased with the increase of reinforcement ratio. At the same age, concrete compressive strength in reinforced concrete specimens saw a gradual reduction when reinforcement ratio increased. A formula was proposed to calculate the compressive strength of concrete in reinforced specimens according to the strength of unreinforced concrete.

scholarly journals Effect of Functional Superplasticizers on Concrete Strength and Pore Structure

2020 ◽  
Vol 10 (10) ◽  
pp. 3496
Author(s):  
Wuju Xun ◽  
Changlong Wu ◽  
Xuefei Leng ◽  
Jiye Li ◽  
Desheng Xin ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
High Performance ◽  
Concrete Strength ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Polycarboxylic Acid ◽  
X Ray Diffraction ◽  
Hydration Rate ◽  
Compressive Strength Of Concrete

The current work investigates the fluidity and the loss of the flow rate of cement paste and mortar over time, as well as the pore structure and compressive strength of concrete and mortar in the presence of functional polycarboxylic acid high-performance water-reducing agents. The hydration rate, hydration products, and pore structure of the concrete containing different functional polycarboxylic acid superplasticizers were analyzed by means of mercury intrusion test, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that water-reducing agent Z significantly improves the pore structure of concrete and further compacts the structure of concrete and mortar, thereby improving the compressive strength of concrete. Moreover, the shorter side chains and ester functional groups in the structure of water-reducing agent H can slow down cement hydration rate, which lowers the early strength of mortar; nevertheless, at later stages, the pore structure of the concrete and mortar including superplasticizer H is less different from that of the concrete and mortar containing polycarboxylic acid water-reducing agents. Water-reducing agent J performs best but has a weaker effect on the pore structure of concrete and mortar compared to superplasticizer Z; it is also better than naphthalene-based water-reducing agents.

scholarly journals Study of Concrete Strength and Pore Structure Model Based on Grey Relation Entropy

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 432
Author(s):  
Min Zhang ◽  
Xianhua Yao ◽  
Junfeng Guan ◽  
Lielie Li ◽  
Juan Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Pore Size ◽  
Concrete Strength ◽  
Sensitivity Coefficient ◽  
Structure Model ◽  
Proposed Model ◽  
Compressive Strength Of Concrete ◽  
The Relationship ◽  
Grey Relation

The Grey Relation Entropy (GRE) theory is used to analyze the sensitive pore size that affects the compressive strength of concrete. The relationship between the strength and pore structure is revised based on the sensitivity coefficient. The revised model is used to calculate the compressive strength of concrete. In order to verify the validity of the proposed model, the calculated results are compared with experimental ones, showing satisfactory agreement with a larger correlation than existing methods.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

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%.

Determination of Concrete Cube Strength from Used Samples / Určení Krychelné Pevnosti Betonu U Použitých Zkušebních Trámců

2012 ◽  
Vol 12 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský
Keyword(s):  
Compressive Strength ◽  
Concrete Beams ◽  
Linear Analysis ◽  
Bending Tests ◽  
Cube Strength ◽  
Non Linear ◽  
Compressive Strength Of Concrete ◽  
Concrete Cube

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.

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