Experimental Study on Frost Resistance of the Shale Ceramsite Concrete

2011 ◽  
Vol 117-119 ◽  
pp. 1754-1758 ◽  
Author(s):  
Wei Jun Yang ◽  
Yong Da Yang ◽  
Yi Yang
Keyword(s):  
Experimental Study ◽  
Frost Resistance ◽  
Absorption Characteristic ◽  
Cement Ratio ◽  
Freeze Thaw ◽  
Air Content ◽  
Mix Proportion ◽  
Study Results ◽  
Wetting Time ◽  
Structure Water

In this presented work, by freeze-thaw test for three groups of shale ceramsite concrete with different mix proportion, the experimental results show: the shale ceramsite concrete has preferable frost resistance property. After 100 times freeze-thaw cycles, its loss in weight and strength is very small; the frost resistance increases as ceramsite pre-wetting time is raised, and with the increasing of the water cement ratio, the frost resistance declines. The statement that ceramsite pre-wetting treatment is detrimental to frost resistance still deserves discussion, as it depends on the pore structure, water absorption characteristic and concrete air content of ceramsite itself. Meanwhile, freeze-thaw mechanism of the shale ceramsite concrete was analyzed in this paper. The study results provide some reference for other studies.

Optimization Research of Mix Proportion of Frost Resistance Construction of Concrete Based on the MATLAB Language

2014 ◽  
Vol 584-586 ◽  
pp. 1917-1921
Author(s):  
Jun Jie Zhang ◽  
Rui Hong Shao ◽  
Xiang Yi Meng
Keyword(s):  
Compressive Strength ◽  
Objective Function ◽  
Frost Resistance ◽  
Unit Volume ◽  
Influence Factors ◽  
Multi Objective Optimization ◽  
Cold Region ◽  
Freeze Thaw ◽  
Performance Indexes ◽  
Mix Proportion

Analyze the influence factors of mix proportion affecting concrete freeze-thaw damage. Use the five main performance indexes of the concrete, which are compressive strength, strength of extension, impermeability grade, and frost resistance grade and per unit volume cost concrete, as the objective function of multi-objective optimization equation. Invoke the fgoalattain function in the MATLAB Optimization Toolbox to solve. The optimized parameters of mix proportion of frost resistance construction of unit concrete in cold region are: concrete 1532.6kg, water 910kg, sand 5510.6kg, 5-20mm cobblestone 3747.2kg、20-40mm cobblestone 3658.6kg、40-80mm cobblestone 4733.5kg、80-150mm cobblestone 4738.1kg, and the dosage of water reducing agent is 7.3kg.

Effect of Saturation Degree on Concrete Deterioration due to Freeze-Thaw Action

2011 ◽  
Vol 477 ◽  
pp. 404-408 ◽  
Author(s):  
Wen Cui Yang ◽  
Yong Ge ◽  
Bao Sheng Zhang ◽  
Jie Yuan
Keyword(s):  
Frost Resistance ◽  
Water Pressure ◽  
High Water ◽  
Frost Damage ◽  
Critical Value ◽  
Cold Weather ◽  
Saturation Degree ◽  
Freeze Thaw ◽  
Air Content ◽  
The Difference

Freezing-thawing durability of cement concrete is extremely important in cold weather, to better understand mechanism of frost damage and air-entraining，saturation degree of pores in concrete and its relation with frost resistance were studied in this paper. Concrete specimens with different saturation degree from 0 to 100% were prepared used a sealed tin with a high water pressure pump. Then these specimens were subjected to six freezing-thawing cycles and the relative dynamic modulus of elasticity was examined. The results showed that critical saturation degree of concrete with water- binder ratio of 0.30 and 0.47, air content of 1%, 4% and 6% were from 0.60 to 0.80. When its saturation degree exceeded the critical value, concrete was deteriorated significantly after only six freeze-thaw cycles. The critical saturation degree was mainly related to the air content of concrete mixture, and it decreased with the increasing of air content. The difference between the saturation degree and the critical value can be used to evaluate potential frost resistance of concrete, and its result was consistent with the result of frost tests very well.

An Experimental Study on the Mechanical Properties of Cemented Rock-Tailings Fill

2014 ◽  
Vol 941-944 ◽  
pp. 2611-2619
Author(s):  
Li Jie Guo ◽  
Ke Ping Zhou ◽  
Xiao Cong Yang ◽  
Guang Sheng Liu ◽  
Wen Yuan Xu
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Mine Waste ◽  
Waste Rock ◽  
Mill Tailings ◽  
Mix Proportion ◽  
Study Results ◽  
Mine Waste Rock ◽  
Materials Used ◽  
Mine Development

This paper outlines an effective approach to making composite backfill using mine waste material. Composite materials are widely used in many areas of engineering because of their unique structural properties. Cemented rock-tailings are one of the most prevalent materials used for composite backfill because they can effectively make use of mine waste rock and mill tailings that would otherwise be simply considered waste. This backfill method has the capability of maintaining the mine environment while still allowing for continued mine development. An experimental study is being conducted in a cooperative mine research project to investigate the properties of backfill material and specifically the mechanical characteristics of cemented waste rock-tailings fill. This study details the characteristics of the composite backfill aggregate with respect to the compressive strength of the cemented rock-tailings fill and the backfill mix-proportion, as well as outlines a new method of study for cemented rock-tailings fill mechanics. The study results show the compressive strength of cemented rock-tailings fill is dependent mainly on the cement and waste rock content. Ensuring a precise backfill mix proportion can effectively reduce the cement dosage, thereby decreasing the backfill cost realized for the mine.

Experimental Study of Mechanical Properties of Concrete after Freeze-Thaw Exposures

2014 ◽  
Vol 912-914 ◽  
pp. 131-135
Author(s):  
Xiang Ping Fu ◽  
Xiao Xue Liu ◽  
Yi Ze Sun ◽  
Pei Huang ◽  
Yu Chen Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Elasticity Modulus ◽  
Concrete Specimen ◽  
Concrete Compressive Strength ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Freeze Thaw ◽  
Cold Area

The experiment studies how the freeze-thaw cycles influence concrete compressive strength and elasticity modulus with different water-cement ratio under the air-entraining agent and zero of that value respectively. It can be found that modulus of elasticity and compressive strength of the concrete specimen reduced significantly when there is air-entraining agent; the durability of freeze-thaw resistance, however, makes great improvement; as the cement increases, both of them improves effectively. Through the comparison of concrete compressive strength and elastic modulus with different water-cement ratio and air-entraining agent, the optimal water-cement ratio and air-entraining agent were determined. The results of experiment can be used in concrete engineering design in severe cold area.

Experimental Study on Freeze Thaw Resistance Concrete

2013 ◽  
Vol 830 ◽  
pp. 41-44
Author(s):  
Fu Yun Yang
Keyword(s):  
Experimental Study ◽  
Frost Resistance ◽  
Orthogonal Experiment ◽  
Research Experience ◽  
Range Analysis ◽  
Mixture Ratio ◽  
Factors Affecting ◽  
Freeze Thaw ◽  
Durability Of Concrete

In this paper, through the domestic and foreign research experience, the orthogonal experiment on some factors affecting the durability of concrete is designed. By range analysis the tests identify the effects of various factors on frost resistance, therefore this paper presents the optimum mixture ratio.

Efficiency Air-Entraining Water-Reducing Agent in Concrete Study on the Freeze-Thaw Resistance

2011 ◽  
Vol 71-78 ◽  
pp. 3566-3571 ◽  
Author(s):  
Mei Yan Hang ◽  
Wei Zhang
Keyword(s):  
Frost Resistance ◽  
Reducing Agent ◽  
Gas Content ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Freeze Thaw

In this paper, the frost resistance on different water-cement ratio of concrete after the air-entraining agent admixture. When the gas is controlled about 4%, with the lower water-cement ratio, freeze-thaw resistance of concrete is increased significantly. And then the frost resistance of YC20 and YC40 concrete which are mixed in efficient air-entraining water-reducing agent were studied, the experiment results that when the concrete YC40 reached F300, gas content reached more than 4.5%,and the strength without reducing, the durability would improve. But the YC20 is different, so, GL-B4-efficiency air-entraining water-reducing agent does not apply to the water-cement ratio above 0.6 of the concrete

Experimental Study on Application Properties of Macroporous Ecological Concrete without Sand

2011 ◽  
Vol 250-253 ◽  
pp. 901-905
Author(s):  
Zhen Xian Xing ◽  
Yi Xing
Keyword(s):  
Experimental Study ◽  
Erosion Resistance ◽  
Necessary Conditions ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Coarse Aggregates ◽  
Effect Of Water ◽  
Resistance Property ◽  
Mix Proportion ◽  
Series Of Experiments

This paper suggests that deposition paste area is one of those leading control indicators of mix proportion design for the macroporous ecological concrete without sand. By analyzing the effect of water-cement ratio, amount of cement, and type of coarse aggregates on application properties of concrete, it puts forward that when carrying out the mix proportion design of the concrete, setting the water-cement ratio as 0.4 can help the macroporous ecological concrete without sand acquire satisfying application properties. Based on this idea, experiments to the later period strengths and the erosion resistance property of concretes are tried out. Finally, the result of this series of experiments shows that the macroporous ecological concrete without sand possesses necessary conditions for plants to survive and grow up.

Experimental Study of Compression and Carbonation in Concrete Subjected to Freeze-Thaw Environment

2014 ◽  
Vol 887-888 ◽  
pp. 814-818
Author(s):  
Li Xue Wang ◽  
Xiao Ting Shan ◽  
Yu Qing Zhang ◽  
Chun Sheng Li ◽  
Zai Xing Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Test Method ◽  
Carbonation Depth ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Freeze Thaw ◽  
Concrete Properties

In order to research the changes of concrete properties in freeze-thaw environment, five concrete samples with water-cement ratio respectively equal to 0.60, 0.65, 0.70, 0.75 and 0.80 were tested in freeze-thaw environment according to GB/T50082-2009 concrete rapid freeze-thaw cycles test method. Five samples were carried out 0, 25, 50, 75, 100 times faster freeze-thaw cycles test. With the increasing number of freeze-thaw cycles, the concrete relative dynamic modulus of elasticity loss rises, the compressive strength drops, and the carbonation depth increases. The greater the water-cement ratio of concrete specimens with freeze-thaw cycles, the greater the degree of damage increases.

Study on the Frost Resistance of Artificial Aggregates Recycled Concrete

2012 ◽  
Vol 509 ◽  
pp. 82-87
Author(s):  
Jin Bang Wang ◽  
Zong Hui Zhou
Keyword(s):  
Elastic Modulus ◽  
Fly Ash ◽  
Silica Fume ◽  
Frost Resistance ◽  
Mechanical Performance ◽  
Recycled Concrete ◽  
Dynamic Elastic Modulus ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Freeze Thaw

The recycled concrete was prepared by using the high-strength artificial aggregates. This kind of concrete can be completely regenerated to be cement, and the recycling utilization of the concrete can also be truly realized. The frost resistance and influencing factors of the recycled concrete were studied. The results show that the mechanical performance and frost resistance of artificial aggregates recycled concrete are better than those of the ordinary concrete under the same water/cement ratio condition. When the water/cement ratio is 0.40, the relative dynamic elastic modulus, weight loss and frost durability factor of the recycled concrete are 98.7%, 0.5% and 65.8 after 200 times freeze-thaw cycles. When the fly ash and silica fume were added into the recycled concrete, the frost resistance can be improved. The optimal amounts of fly ash and silica fume are 30% and 15% of cement by weight, respectively. The recycled concrete was prepared with the optimal fly ash and silica fume content, respectively. After 200 times freeze-thaw cycles, the relative dynamic elastic modulus of the recycled concrete are 99.1% and 99.2%, and the weight losses of the recycled concrete are 0.4% and 0.3%, and antifreeze durability coefficient of the recycled concrete are 66.07 and 66.13. Therefore, the recycled concrete with silica fume has better frost resistance performance than that with fly ash as admixture.

Experimental Study on Thermal Conductivity of Road Concrete

2012 ◽  
Vol 178-181 ◽  
pp. 1573-1576
Author(s):  
Yan Cong Zhang ◽  
Ling Ling Gao ◽  
Jun Min Shen
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Fly Ash ◽  
Coarse Aggregate ◽  
Gas Content ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Air Content ◽  
Main Factor

In order to analyses affection to thermal conductivity from various factors, such as: coarse aggregate, mortar ratio, sand ratio, water cement ratio, fly ash and air content, thermal conductivity of a series of concrete specimens were determined based on thermal conductivity meter. The results showed that: coarse aggregate, mortar ratio and gas content is the main factor affecting concrete thermal conductivity. Meanwhile, water-cement ratio, sand ratio and fly ash had few effects on the thermal conductivity. In addition, a certain formula to predict thermal conductivity of concrete was proposed.

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