Study the Relationship between the Concrete Strength Added Water Reducer and Water-Cement Ratio

2013 ◽  
Vol 405-408 ◽  
pp. 2625-2630
Author(s):  
Peng Gao ◽  
Chen Yu Jiang
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Calculation Formula ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Quantitative Calculation ◽  
Added Water ◽  
The Relationship

Abstract: Efficient water reducer plays a key role in the allocation of high performance concrete. The experiment uses four grades concrete of C15, C20, C25 and C30 by setting the different water-cement ratio. Each grade is divided into adding water reducing agent and not adding.To test the concrete strength of eight groups by testing compressive strength gains the relationship between the concrete strength added water reducer and water-cement ratio. Through processing experimental data, to get the role water reducer played in conditions of different water cement ratio. What’s more, to gain the corresponding quantitative calculation formula by exerting the regression analysis.

scholarly journals تأثير إستخدام خبث أفران مجموعة جياد الصناعية على جودة الخرسانة

2021 ◽  
Vol 9 (2) ◽  
pp. 1-6
Author(s):  
علي حسين محمد علي ◽  
الطيب عبداللطيف أحمد حبيب
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Hardened Concrete ◽  
Gradual Reduction ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Artificial Materials ◽  
Percent Increase ◽  
And Performance ◽  
Furnace Slag

The need to produce high performance concrete led the researchers to try to exploit the potentialities of natural or artificial materials so as to improve the properties and performance of concrete. Slag is an industrial disposal which considered as a secondary product of pig-iron, these disposal will cause a severe harm to the environment in case of not get rid of it. In this investigation iron furnace slag which is produced at Giad Group - Iron Factory has been used as an alternative of proportion on cement after being processed, since its main oxides are similar to those of cement. In the practical part of our research slag has been added to the concrete mix in two ways, first by using it to replace as cement by weight as a substitutions of cement in different percent [10, 20, 30]% without changing in water-cement ratio [W/C], second by using the slag with the same previous percentage in addition to [15, 25]% to replace cement with reducing in water-cement ratio [W/C], and in addition superplasticizer [SP 901] has been added as percent from cement used in the mixture. The effect of slag was studied on the properties of fresh and hardened concrete including slump test and compressive strength in [7, 14, 28] days were investigated. The results show improvement in all concrete specimens for the added percentage of the slag as replacement materials and the addition of superplasticizer in the production of concrete and improvement in its properties. However, there is a gradual reduction in slump measurements due to slag percent increase in case of the two methods.  

Research Progress on Early Autogenous Shrinkage of Cement-Based Cementitious Materials

2013 ◽  
Vol 634-638 ◽  
pp. 2738-2741
Author(s):  
Wei Huang ◽  
Tao Zhang ◽  
Yun Yun Xu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Research Work ◽  
Autogenous Shrinkage ◽  
Cementitious Materials ◽  
Mineral Admixtures ◽  
Research Progress ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Improvement Measures

Concrete autogenous shrinkage phenomenon would adversely affect the mechanical properties and durability of concrete, this phenomenon is important. Autogenous shrinkage problem of low water-cement ratio of the with high mineral admixtures, cement-based cementitious materials was introduced. The main reason for high-performance concrete early cracking being autogenous shrinkage was pointed out. Based on the home and abroad research status of low water cement ratio of the cement paste and concrete autogenous shrinkage, especially for early autogenous shrinkage phenomenon, the mechanism of autogenous shrinkage and the measure method is presented, and the improvement measures and the possible problems the need for further research work is presented.

scholarly journals Analysis of the Influence of Water-cement Ratio on Concrete Strength

2021 ◽  
Vol 283 ◽  
pp. 01016
Author(s):  
Wei Li
Keyword(s):  
Concrete Strength ◽  
Test Results ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Large Stone ◽  
Regular Change ◽  
Small Stone ◽  
Influence Of Water ◽  
The Relationship

In this paper, the main strength of the relationship between water-cement ratio and concrete, and it uses the contrast test of different water cement ratio, finally, it gets the regular change between water cement ratio and concrete strength. The test results show that: cement. when the ratio of large stone: small stone: water: admixture is 340: 618: 1009: 433: 139: 6.8, the water-cement ratio of concrete is within the range of 0.371-0.479. The concrete strength of the sample decreases with the increase of the water-cement ratio. Finally, the relationship between the concrete strength and the water-cement ratio is obtained by fitting.

scholarly journals Autogenous Shrinkage of HPC and Ways to Mitigate it

2014 ◽  
Vol 629-630 ◽  
pp. 3-20 ◽  
Author(s):  
Klaas van Breugel ◽  
Nguyen van Tuan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Substantial Part ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Dense Microstructure ◽  
Increased Risk ◽  
Current Design ◽  
Normal Strength

Autogenous shrinkage strains may cause cracking of brittle cement-based systems. The lower the water/cement ratio of a mixture, the higher the autogenous shrinkage and the higher the probability of cracking. Cracking increases the probability of ingress of aggressive substances into the concrete, jeopardizing the durability of the material. Low water/cement ratios, however, result in a dense microstructure, which is one of the desired features of high performance concrete because of the assumed increase in durability. This results in a kind of dilemma: the high density of low water/cement ratio concretes is desired, but the increased risk of (micro) cracking of these mixtures, of course, not. This dilemma is discussed in this contribution. The search for ways to get out of this dilemma starts with understanding the mechanisms of autogenous shrinkage. It is shown that autogenous shrinkage is not only an issue in low water/cement ratio mixtures. In normal strength concretes, with w/c ratios between 0.40 – 0.50, autogenous shrinkage can make out a substantial part of the total strain. Ways to mitigate autogenous shrinkage of mixtures with water/binder ratios ranging from 0.18 to 0.50 are discussed. Finally brief comments are made on autogenous shrinkage values prescribed in current design codes.

Test and Application of High Performance Concrete

2014 ◽  
Vol 908 ◽  
pp. 30-33
Author(s):  
Ping Tan ◽  
Yan Min Zhao ◽  
Qiu Hong Meng
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Raw Materials ◽  
High Strength ◽  
High Volume ◽  
Economic Benefits ◽  
Mineral Admixtures ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Volume Stability

The durability of high performance concrete is the main index of design. design.With the high durability, the high volume stability,the high compressive strength and the good workability, high performance concrete widely used in high-rise buildings, large-span Bridges, offshore in the construction of buildings, roads, etc.This paper prepared with different water/cement ratio of high performance concrete and tested the concrete workability, mechanical properties, durability.High performance concrete need preparate with low water/cement ratio, choose high quality raw materials,adding a sufficient number of mineral admixtures and high-performance admixture. Useing the high strength and high performance concrete can decrease the size of cross section, lose weight, gain greater economic benefits.

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

Study on corrosion effect of high-performance concrete under the action of sulfate and chlorine

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940054 ◽  
Author(s):  
Rongrong Yin ◽  
Jie Hu ◽  
Yu Liu ◽  
Qing Wu ◽  
Chenchen Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Growth Stage ◽  
High Performance Concrete ◽  
Slow Growth ◽  
Concrete Strength ◽  
Corrosion Damage ◽  
Chloride Salt ◽  
Single Action ◽  
Two Stages

The thickness of corroded concrete layer and the compressive strength of prisms under the action of sulfate and chloride salt were investigated by ultrasonic test and compression test, respectively. The results show that under the single action of sulfate, the strength of concrete experienced two stages: a slow growth stage and a rapid descent stage. Correspondingly, under the combined action of sulfate and chloride, the concrete strength experienced another two stages: a slow growth stage and a slow degradation stage. The existence of chloride inhibited the corrosion damage of concrete in a certain extent. It was found that higher concentration of chlorine salt would lead to a stronger inhibition effect. A good consistency was observed among corrosion layer thickness, compressive strength and X-ray diffraction results. The inhabitation of chloride to the sulfate corrosion of concrete was proved.

scholarly journals Effect of water/cement ratio on micro-nanomechanical properties of the interface between cementitious matrix and steel microfibers in ultra-high performance cementitious composites

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Vanessa Fernandes Cesari ◽  
Fernando Pelisser ◽  
Philippe Jean Paul Gleize ◽  
Milton Domingos Michel
Keyword(s):  
Transition Zone ◽  
Cement Paste ◽  
Calcium Silicate ◽  
High Performance ◽  
Calcium Silicate Hydrate ◽  
Interfacial Transition Zone ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Nanomechanical Properties ◽  
Cementitious Matrix

abstract: Ultra-high performance concretes with steel microfibers have been studied in depth with the aim of producing more efficient and durable structures. The performance of these materials depends on the characteristics of the interface between microfibers and cementitious matrix. This research investigates the micro-nanomechanical properties of the interfacial transition zone between the steel microfibers and the matrix of ultra-high performance cementitious composite. The effect of the water/cement ratio and distance from the microfiber were analyzed. The results confirm the formation of high-density calcium-silicate-hydrate (HD C-S-H) matrix at higher concentrations than low-density calcium-silicate-hydrate (LD C-S-H) for w/c ratios of 0.2 and 0.3. The properties in cementitious matrix interface with steel microfibers were very similar to that measured for the cement paste, and no significant difference was observed regarding the distance to the microfibers in relation to the elastic modulus, hardness and chemical composition. Thus, the authors can conclude that the formation of a less resistant region does not occur at the interfacial transition zone cement paste/microfibers.

scholarly journals Tests of Residual Shear Transfer Strength of Concrete Exposed to Fire

2018 ◽  
Vol 64 (2) ◽  
pp. 187-199
Author(s):  
Muhaned A. Shallal ◽  
Aqil Mousa K. Al Musawi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Real Life ◽  
Shear Plane ◽  
Concrete Cover ◽  
Experimental Program ◽  
Fire Exposure ◽  
Structural Components ◽  
Shear Transfer

AbstractReinforced concrete is one of the most widely used structural components about which much scientific research has been conducted; however, some of its characteristics still require further research. The main focus of this study is the effect of direct fire on the shear transfer strength of concrete. It was investigated under several parameters including concrete strength, number of stirrup legs (the steel area across the shear plane), and fire duration. The experimental program involved the testing of two sets (groups) of specimens (12 specimens each) with different concrete strengths. Each set contained specimens of two or four stirrup legs exposed to direct fire from one side (the fire was in an open area to simulate a real-life event) for a duration of one, two, and three hours. The results of the comparison showed the importance of using high-performance concrete (instead of increasing the number of stirrup legs) to resist shear stress for the purpose of safety. A significant reduction in shear strength occurred due to the deterioration of the concrete cover after three hours of direct fire exposure.

Research and Applying Evolution of High Efficient Water-Reducing Agent for High Performance Concrete

2012 ◽  
Vol 610-613 ◽  
pp. 573-576
Author(s):  
Zheng Jun Wang ◽  
Jia Bin Liang
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Reducing Agent ◽  
Mass Concrete ◽  
Green Concrete ◽  
High Efficient ◽  
Strength And Durability

This paper discusses the development of water-reducing agent and the present situation of the application of high performance concrete. The traditional concrete will be substituted by high performance concrete, green concrete. In the course of appearance of high performance and green, concrete admixtures plays an extremely important role. Concrete water-reducing agent is admixture of the main part. In the case of keeping liquidity, it can make water consumption reduce, so the concrete strength and durability can be improved. It is applicable to all kinds of industrial and civil construction engineering, and it can be applied to different strength grade of concrete. It has important significance for mass concrete engineering, marine building facilities, and component and product of high strength lightweight concrete.

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