Experiment Design on Concrete under Load Attacked by Acid Rain

2011 ◽  
Vol 243-249 ◽  
pp. 5760-5763
Author(s):  
Jian Gang Niu ◽  
Zhen Zhang ◽  
Di Tao Niu
Keyword(s):  
Fly Ash ◽  
Acid Rain ◽  
Concrete Structures ◽  
Experiment Design ◽  
Durability Test ◽  
Predicting Model ◽  
Fly Ash Concrete

As the deterioration of environment, the effect of acid rain on concrete structures is even more serious. The durability problems caused by acid rain are increasingly concerned by the worldwide. In this paper, the method to simulating acid rain solution in laboratory is proposed and the cyclic soaking-drying to accelerate the acid rain attack is introduced on the basis of the survey and analysis on the components of acid rain around China. Considering that the majority of concrete structures are actually under loads, the load devices for durability test are analyzed, and the devices suitable for the multi-factor durability tests are adopted. The above works will be helpful to carry out the neutralization tests and establish the predicting model of neutralization depth for fly ash concrete.

Fly-Ash Concretes of 50% of the Replacement Ratio to Reduce the Cracking in Concrete Structures

2013 ◽  
Vol 405-408 ◽  
pp. 2665-2670 ◽  
Author(s):  
Ming Jie Mao ◽  
Qiu Ning Yang ◽  
Wen Bo Zhang ◽  
Isamu Yoshitake
Keyword(s):  
Fly Ash ◽  
Concrete Structures ◽  
High Volume ◽  
Pozzolanic Reaction ◽  
Strength Development ◽  
Early Age ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Massive Concrete ◽  
Normal Strength

Fly-ash concrete used in massive concrete structure has superior advantages to reduce hydration heat. On the other hand, the fly-ash concrete has negative property of low strength development at early age because pozzolanic reaction of fly-ash activates at mature age, such as after 28 days. To investigate these characteristics of fly-ash used in concrete, the present study discusses thermal cracking possibility of fly-ash concrete by using FE analysis software. The present study employs prediction formulae proposed by Zhang and Japanese design code in the simulations. The objects in this study are normal strength concrete mixed of fly-ash up to 50% of replacement ratio to cement. The comparative investigations show that temperature effect is more significant than strength development at early age. Based on the analytical study, high volume fly-ash concretes of 30-50% of the replacement ratio can be concluded as effective and useful materials to reduce the cracking possibility in massive concrete structures. Keywords-Fly-ash concrete; Early Age, Prediction Formulae for Strength; Thermal Stress Analysis

Evaluation of Relations among Basic Mechanical Properties of Fly-Ash Concrete with Machine-Made Sand

2013 ◽  
Vol 438-439 ◽  
pp. 15-19
Author(s):  
Chun Jie Liu ◽  
Chun Yan Jia ◽  
Chang Yong Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Concrete Structures ◽  
Ordinary Concrete ◽  
Strength Grade ◽  
Fly Ash Concrete ◽  
Axial Compressive Strength

Although the machine-made sand was widely used for concrete in recent years in China, it was short of studies on the relations among the basic mechanical properties of fly-ash concrete with machine-made sand (MSFAC). However, these relations such as the compressive strength, the tensile strength and the elastic modulus with the cubic compressive strength (i.e. strength grade) are the basis of design for concrete structures. This paper summarizes the test data from the published references, and discusses the relations among these properties by statistical analyses compared with those of ordinary concrete. The results show that only the tensile strength of MSFAC can be safely forecasted by the same formula of ordinary concrete specified in current Chinese design code. When the strength grade is higher than C45, the axial compressive strength of MSFAC is largely forecasted by the formula of ordinary concrete. The elastic modulus of MSFAC is larger than that of ordinary concrete, which should be prospect by the formula in this paper. This work gives out some cautions for the proper use of the MSFAC in concrete structures.

scholarly journals Life cycle sustainability assessment of fly ash concrete structures

2017 ◽  
Vol 80 ◽  
pp. 1162-1174 ◽  
Author(s):  
JingJing Wang ◽  
YuanFeng Wang ◽  
YiWen Sun ◽  
Danielle Densley Tingley ◽  
YuRong Zhang
Keyword(s):  
Life Cycle ◽  
Fly Ash ◽  
Sustainability Assessment ◽  
Concrete Structures ◽  
Life Cycle Sustainability Assessment ◽  
Fly Ash Concrete

Investigation on Neutralization Rules of Concrete under Loads Subjected to Acid Rain Attack

2011 ◽  
Vol 243-249 ◽  
pp. 5768-5771
Author(s):  
Jian Gang Niu ◽  
Hai Tao Zhai ◽  
Di Tao Niu
Keyword(s):  
Fly Ash ◽  
Tensile Stress ◽  
Acid Rain ◽  
Compressive Stress ◽  
Stress Level ◽  
Fly Ash Concrete ◽  
Concrete Corrosion ◽  
Simultaneous Attack

The neutralization of fly ash concrete under loads subjected to the simultaneous attack of acid rain was investigated in this paper. And the influence of stress level and fly ash replacement on neutralization of fly ash concrete was analyzed. It was found that, the bending tensile stress accelerated the acid rain attack. The higher the stress level, the more serious the concrete corrosion. In contrast, the bending compressive stress slowed down the acid rain attack. The results also showed that the neutralization depth of fly ash concrete was increasing and concrete corrosion attacked by acid rain was more serious as the fly ash replacement increased.

scholarly journals Carbonization Law of Fly Ash Concrete under Freeze-Thaw Cycles Based on Image-Pro Plus

2020 ◽  
Vol 44 (6) ◽  
pp. 393-398
Author(s):  
Jing Yuan ◽  
Boxin Zhao ◽  
Zhenqiang Wang ◽  
Yan Liu
Keyword(s):  
Fly Ash ◽  
Linear Relationship ◽  
Concrete Structures ◽  
Ash Content ◽  
Experimental Results ◽  
Freeze Thaw ◽  
Fly Ash Concrete ◽  
Convergence Point ◽  
Research Findings

To understand the influence of freeze-thaw on the carbonization performance of concrete in severe cold areas, this paper conducted experiments to explore the carbonization law of fly ash concrete under freeze-thaw cycles. First, carbonization tests were conducted under different freeze-thaw cycles and fly ash contents; then PS (Photoshop) and IPP (Image-Pro Plus) were adopted to measure the carbonized area and calculate the ratio of carbonized area (RCA). The experimental results showed that, when the fly ash content was between 10% and 30%, RCA increased slowly; when the fly ash content was 20%, the convergence point showed up; when the fly ash content was 0, the air-entrained fly ash concrete had the best resistance to carbonation. With the help of PS and IPP, this paper calculated the RCA more accurately and found that, the freeze-thaw cycles can aggravate carbonization, and there is a linear relationship between carbonization depth and RCA. The research findings in this paper can provide a reference for the durability evaluation and design of concrete structures in severe cold areas.

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