scholarly journals volumechange and strength characteristics of normal and high-strength mortars: effect of aggregate type and water-binder ratio

2018 ◽  
Vol 5 (1) ◽  
pp. 1542928 ◽  
Author(s):  
Ali H. Nahhab ◽  
Ghaida Faeq A. Zahra ◽  
Anil Kumar Choudhary
Keyword(s):  
High Strength ◽  
Strength Characteristics ◽  
Binder Ratio ◽  
Water Binder Ratio

Study on Tensile Creep Characteristics of High Strength Concrete

2016 ◽  
Vol 835 ◽  
pp. 535-541
Author(s):  
Guan Guo Liu ◽  
Guo Rong Zhang ◽  
Yun Sheng Zhang ◽  
Lu Lu
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Creep Testing ◽  
Tensile Creep ◽  
Free Shrinkage ◽  
Inhibition Effect ◽  
Creep Characteristics ◽  
Binder Ratio ◽  
Water Binder Ratio

A set of concrete tensile creep testing apparatus was constructed. The tensile creep characteristics of concrete under different loading ages (1d, 3d and 7d), different water-binder ratio (0.29, 0.33 and 0.37) and different fly ash proportion (0%, 20% and 40%) were researched. The results show that tensile creep increases with increasing of water-binder ratio obviously as well as with decreasing of loading ages. The tensile creep is inhibited by addition of fly ash, and the inhibition effect increases with the increase of fly ash proportion. Free shrinkage is counteracted 42%~62% by tensile creep. The internal tension of concrete is effectively relieved so that the possibility of cracking of concrete is decreased at early ages.

Proportion Design of Autoclaved Cement Concrete Based on High Strength

2011 ◽  
Vol 391-392 ◽  
pp. 161-164
Author(s):  
Tie Quan Ni ◽  
Chang Jun Ke ◽  
Li Zhang
Keyword(s):  
Coarse Aggregate ◽  
High Strength ◽  
Orthogonal Test ◽  
Mineral Admixture ◽  
Mix Design ◽  
Hydration Reaction ◽  
Cement Concrete ◽  
Binder Ratio ◽  
Four Levels ◽  
Water Binder Ratio

According to the particularity of the autoclaved cement concrete that partial aggregate could participate in hydration reaction in the process of autoclaving, the optimal gradation of coarse aggregate and the optimal slurry aggregate ratio is studied, and the effect of water reducing agent for fluidity of cement paste is also studied. The optimized mix design of autoclaved cement concrete based on high strength (compressive strength and flexural strength) is done by orthogonal test with four factors (water-binder ratio, type of mineral admixture, amount and sand ratio) and four levels.

scholarly journals Use of condensed silica fume for making high-strength, self-consolidating concrete

2000 ◽  
Vol 27 (4) ◽  
pp. 620-627 ◽  
Author(s):  
A KH Kwan
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Self Consolidating Concrete ◽  
Concrete Mix ◽  
Binder Ratio ◽  
Condensed Silica Fume ◽  
Water Binder Ratio

A high concrete strength can be achieved by lowering the water/binder ratio and a high workability by adding a higher dosage of superplasticizer. However, a high-performance concrete with both high strength and high workability cannot be produced by just these means because lowering the water/binder ratio leads to lower workability and there is a limit to the increase in workability that can be attained by adding superplasticizer. To produce a high-strength, high-workability concrete, the concrete strength needs to be increased without lowering the water/binder ratio. This can be done by adding condensed silica fume. In this study, a series of trial mixing aimed at developing high-strength, self-consolidating concrete (mean cube strength >80 MPa and needs no compaction for consolidation) was carried out. Several mixes suitable for making such high-performance concrete have been developed and it was found that the addition of condensed silica fume may, under favourable conditions, increase not only the strength but also the workability of the concrete mix. Based on the trial mix results, charts for the design of high-strength, high-workability concrete mixes made of the studied constituents are presented.Key words: condensed silica fume, high-strength concrete, self-consolidating concrete.

Research on the Mixture Ratio Design of Ultra-High Strength Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2782-2788
Author(s):  
Li Bin Xu ◽  
Nai Qian Feng ◽  
Kia Hui Tew
Keyword(s):  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Mineral Admixtures ◽  
Relevant Parameter ◽  
Concrete Technology ◽  
Mixture Ratio ◽  
Strength Concrete ◽  
Binder Ratio ◽  
Water Binder Ratio

Ultra-high strength concrete (including the coarse aggregate of over 5mm), with high compressive strength and strong durability, is regarded as a new-type building material that could economize on raw materials, land and energy and the development trend of concrete technology both at home and abroad. However, the large consumption of binding materials, low water-binder ratio and the viscous mixture are prone to give rise to the inferior pumping capacity, pipe blockage and pipe break, thus preventing its massive application in the real projects. Therefore, through the design of reasonable mixture ratio, this paper makes up and produces the pumping ultra-high strength concrete of over 100MPa that contains coarse aggregate by adopting the compound design of mineral admixtures, such as slag powder, fly ash and ganister sand so as to optimize the relevant parameter of the mixture ratio. Finally it comes to the conclusion that while making up the ultra-high strength concrete of over 100MPa, it is much more reasonable to appropriately add the mixing amount of the mineral admixtures, increase the water-cement ratio and decrease the water-binder ratio.

Studies on Influence of Mineral Admixtures on High Performance Concrete Gas Permeability

2011 ◽  
Vol 99-100 ◽  
pp. 762-767 ◽  
Author(s):  
Xian Tang Zhang ◽  
Kang Ning Gao ◽  
Xiao Chen Zhou ◽  
Hong Li Wang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Gas Permeability ◽  
Reference Value ◽  
High Strength ◽  
Mineral Admixtures ◽  
Concrete Durability ◽  
Close Relationship ◽  
Binder Ratio ◽  
Water Binder Ratio

There is a close relationship between the gas permeability of modern high strength concrete and the concrete durability. Through the Cembureau method, gas permeability coefficients of ordinary concrete and concrete with admixtures under different maintenance periods were tested. We studied the influence of fly ash and slag on high performance concrete gas permeability, and analysed the rules of gas permeability changing with mineral admixtures and the water-binder ratio, and gave the reasonable range of mineral admixtures and the water-binder ratio. The results from the paper may have the certain reference value to practical application.

scholarly journals The Rapid Chloride Migration Test in Assessing the Chloride Penetration Resistance of Normal and Lightweight Concrete

2021 ◽  
Vol 11 (16) ◽  
pp. 7251
Author(s):  
Jorge Pontes ◽  
José Alexandre Bogas ◽  
Sofia Real ◽  
André Silva
Keyword(s):  
Lightweight Concrete ◽  
Chloride Transport ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Simple Method ◽  
Chloride Migration ◽  
Binder Ratio ◽  
Chloride Penetration Resistance ◽  
Water Binder Ratio

Chloride-induced corrosion has been one of the main causes of reinforced concrete deterioration. One of the most used methods in assessing the chloride penetration resistance of concrete is the rapid chloride migration test (RCMT). This is an expeditious and simple method but may not be representative of the chloride transport behaviour of concrete in real environment. Other methods, like immersion (IT) and wetting–drying tests (WDT), allow for a more accurate approach to reality, but are laborious and very time-consuming. This paper aims to analyse the capacity of RCMT in assessing the chloride penetration resistance of common concrete produced with different types of aggregate (normal and lightweight) and paste composition (variable type of binder and water/binder ratio). To this end, the RCMT results were compared with those obtained from the same concretes under long-term IT and WDT. A reasonable correlation between the RCMT and diffusion tests was found, when slow-reactive supplementary materials or porous lightweight aggregates surrounded by weak pastes were not considered. A poorer correlation was found when concrete was exposed under wetting–drying conditions. Nevertheless, the RCMT was able to sort concretes in different classes of chloride penetration resistance under distinct exposure conditions, regardless of the type of aggregate and water/binder ratio.

Effects of Two Polypropylene Fibers on the Properties of High Strength Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1328-1331
Author(s):  
Bai Rui Zhou ◽  
Dong Dong Han ◽  
Jian Hua Yang ◽  
Yi Liang Peng ◽  
Guo Xin Li
Keyword(s):  
Portland Cement ◽  
Modulus Of Elasticity ◽  
High Strength Concrete ◽  
Polypropylene Fiber ◽  
High Strength ◽  
Polypropylene Fibers ◽  
Strength Concrete ◽  
Reticular Fiber ◽  
Binder Ratio ◽  
Water To Binder Ratio

Portland cement, crushed stone, sand and superplasticizer were used to obtain a high strength concrete with a low water to binder ratio. A reticular polypropylene fiber and a single polypropylene fiber were used to improve the strength of the high strength concrete, but the effects of the two fibers on the slump and strengths were quite different. The reasons of the differences were the surface area and the modulus of elasticity of the fibers. The results show the reticular fiber was better to used in high strength concretes.

Experimental Research of the Durability, Crack Resistance of the Normal Sections of Bending Elements Produced of Rubber Concrete with Fiber and their Deformability

2018 ◽  
Vol 931 ◽  
pp. 232-237 ◽  
Author(s):  
Aleksei E. Polikutin ◽  
Yuri B. Potapov ◽  
Artem V. Levchenko
Keyword(s):  
Crack Resistance ◽  
Experimental Research ◽  
High Strength ◽  
Strength Characteristics ◽  
Material Consumption ◽  
Load Bearing ◽  
Fiber Concrete ◽  
Rubber Concrete ◽  
Concrete Elements

The article describes experimental research of bending rubber fiber concrete elements with favorable deformation-strength characteristics. The use of such a material as fiberrubcon in load-bearing structures due to its high strength leads to a decrease in material consumption and weight of structures.

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