Research of Steel Fiber Self-Compacting Concrete Frost Resistance

2012 ◽  
Vol 174-177 ◽  
pp. 721-725 ◽  
Author(s):  
Ming Bao Gao ◽  
Yan Ru Zhao ◽  
Xiao Yan He
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Steel Fiber ◽  
Concrete Specimen ◽  
Test Method ◽  
Dynamic Elastic Modulus ◽  
Self Compacting Concrete ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

With the fast freeze-thaw test method, the c50 steel fiber self-compacting concrete was carried out 300 tests of freeze-thaw cycle. In the process of freeze-thaw cycles, it determined by the quality of the concrete specimen, dynamic elastic modulus and strength, and analyzed the steel fibers and their different contents on frost resistance of self-compacting concrete impact. The results showed that: steel fiber self-compacting concrete in freeze-thaw cycle can play constrained role in the quality loss, dynamic elastic modulus and intensity, and can significantly improve the self-compacting concrete frost resistance. Within a certain range, the more steel fiber, the stronger of frost resistance.

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

The Mechanics Performance of C30 Concrete with Manufactured-Sand under Condition of Freeze-Thaw Cycles

2011 ◽  
Vol 71-78 ◽  
pp. 1036-1039
Author(s):  
Gui Feng Liu ◽  
Zheng Fa Chen ◽  
Xue Xing Chen
Keyword(s):  
Elastic Modulus ◽  
Acid Corrosion ◽  
Experimental Studies ◽  
Raw Material ◽  
Dynamic Elastic Modulus ◽  
Manufactured Sand ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Mechanics Performance ◽  
Freeze Thaw Cycle

Although many people discussed the strength and durability of concrete with natural sand in severe environment, few people investigated the mechanics performance of concrete with manufactured-sand under condition of freeze-thaw cycle, at present. Experimental studies on C30 concrete with manufactured-sand were carried out under condition of freeze-thaw cycle, which based on the testing of raw material performance and concrete mix ration, in this paper. Comparative studies on the changing laws of the mass, strength and the relative dynamic elastic modulus of concrete were developed in three cases which were freeze-thaw cycle, freeze-thaw cycle and acid corrosion and freeze-thaw cycle and alkali corrosion. The test results showed that the mass, strength and the relative dynamic elastic modulus of concrete with manufactured-sand decreased evidently with the increasing of times of freeze-thaw cycle. The durability of acid and alkali-resistant of concrete with manufactured-sand was also remarkably weakened due to the action of freeze-thaw cycle. The capability of acid and alkali-resistant of the concrete was decreased with the increasing of times of freeze-thaw cycle and the anti-acid capability was decreased more seriously.

scholarly journals Mechanical Properties and Micro Structure of Cement Concrete in Freeze-Thaw Environment

2021 ◽  
Vol 233 ◽  
pp. 01011
Author(s):  
Xin jian Lv ◽  
Lei Yu ◽  
Ming ming Chai
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Pore Structure ◽  
Fresh Water ◽  
Pore Diameter ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Salty Water ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

In order to find the declay law of mechanical property and the performance difference after salty water and fresh water freeze-thaw cycle, freeze-thaw cycle environments under the salty water and fresh water are simulated. The compressive strength, dynamic elastic modulus and the mass lost are tested. The pore structure parameters are also tested by MIP. Plot the pore diameter distribution curve. The result shows that the compressive strength and dynamic elastic modulus are all decreased. The degree of these two properties decreasing under salty water freeze and thaw recycle is more than the one under fresh water. The parameters of porosity and critical pore diameter become larger. The amount of pores whose diameter is between 100nm and 1000nm increase. The amount of pores whose diameter is under 100nm decrease. The deteriorate degree of pore structure is deeper in salty water than in fresh water.

Experimental Study on Freeze-Thaw Resistance of Concrete with Proto-Machine-Made Sand

2011 ◽  
Vol 71-78 ◽  
pp. 4361-4364 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xin Xin Ding ◽  
Shun Bo Zhao ◽  
Zhan Fang Ge
Keyword(s):  
Experimental Study ◽  
Elastic Modulus ◽  
Mass Loss ◽  
Source Rock ◽  
Crushed Stone ◽  
Dynamic Elastic Modulus ◽  
Cycle Times ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

Experiments were conducted to study the effects of source rock state and stone powder on freeze-thaw resistance of concrete with proto-machine-made sand, the strength grade of concrete was C50, the source rock states were gravel and crushed stone, the contents of stone powder in sand were 5%, 9% and 13% respectively. The values of relative dynamic elastic modulus and mass of concrete at different freeze-thaw cycle times were measured, the reduction of relative dynamic elastic modulus and mass loss were calculated to evaluate the freeze-thaw resistance of concrete. The results show that freeze-thaw resistances are controlled by the reduction of relative dynamic elastic modulus of concrete, which are good of concrete with proto-machine-made sand of gravel and crushed stone, and increases with the increasing content of stone powder in sand made of gravel. The reasons leading to difference of freeze-thaw resistance of concrete with sand made of gravel and crushed stone are discussed.

Experimental Study on Frost Resistance Properties of Pumice Mixed Aggregate Concrete

2012 ◽  
Vol 476-478 ◽  
pp. 1661-1664
Author(s):  
Jun Fang Huo ◽  
Jian Jun Chu ◽  
Hui Yang
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Frost Resistance ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Strength Loss ◽  
Dynamic Elastic Modulus ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Thaw Cycle

Different amount of pumice were used to replace gravel to make mixed aggregate concrete, the fast freeze-thaw cycle test were conducted and the influence of pumice rate substitution to the frost resistance properties of concrete were studied.The mass loss rate, strength loss and relative dynamic elastic modulus were regarded as the evaluation index of frost resistance properties of concrete. Results showed that the mass loss rate and strength loss rate gradually decreased and the relative dynamic elastic modulus gradually increased with the increase of pumice rate, the mass loss rate, strength loss rate and the relative dynamic elastic modulus gradually decreased with the increase of freeze-thaw cycles. Polypropylene fibers could reduce the strength loss rate, improved the relative dynamic elastic modulus, but had little effect to improve the mass loss. Through the frost resistance, the frost resistance of concrete improved with the increase of pumice content, at the same time, polypropylene fiber also could improve the frost resistance of concrete.

scholarly journals Use of Silica Fume and GGBS to Improve Frost Resistance of ECC with High-Volume Fly Ash

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yushi Liu ◽  
Xiaoming Zhou ◽  
Chengbo Lv ◽  
Yingzi Yang ◽  
Tianan Liu
Keyword(s):  
Elastic Modulus ◽  
Sodium Chloride ◽  
Mass Loss ◽  
Frost Resistance ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Tap Water ◽  
High Volume ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw

Fly ash (FA) has been an important ingredient for engineered cementitious composite (ECC) with excellent tensile strain capacity and multiple cracking. Unfortunately, the frost resistance of ECC with high-volume FA has always been a problem. This paper discusses the influence of silica fume (SF) and ground-granulated blast-furnace slag (GGBS) on the frost resistance of ECC with high volume of FA. Four ECC mixtures, ECC (50% FA), ECC (70% FA), ECC (30% FA + 40% SL), and ECC (65% FA + 5% SF), are evaluated by freezing-thawing cycles up to 200 cycles in tap water and sodium chloride solution. The result shows the relative dynamic elastic modulus and mass loss of ECC in sodium chloride solution by freeze-thaw cycles are larger than those in tap water by freeze-thaw cycles. Moreover, the relative dynamic elastic modulus and mass loss of ECC by freeze-thaw cycles increase with FA content increasing. However, the ECC (30% FA + 40% SL) shows a lower relative dynamic elastic modulus and mass loss, but its deflection upon four-point bending test is relatively smaller before and after freeze-thaw cycles. By contrast, the ECC (65% FA + 5% SF) exhibits a significant deflection increase with higher first cracking load, and the toughness increases sharply after freeze-thaw cycles, meaning ECC has good toughness property.

scholarly journals Mechanical Properties and Freeze–Thaw Durability of Basalt Fiber Reactive Powder Concrete

2020 ◽  
Vol 10 (16) ◽  
pp. 5682
Author(s):  
Wenjun Li ◽  
Hanbing Liu ◽  
Bing Zhu ◽  
Xiang Lyu ◽  
Xin Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Loss Rate ◽  
Steel Fiber ◽  
Basalt Fiber ◽  
Reactive Powder Concrete ◽  
Chloride Salt ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Reactive Powder

Basalt fiber has a great advantage on the mechanical properties and durability of reactive powder concrete (RPC) because of its superior mechanical properties and chemical corrosion resistance. In this paper, basalt fiber was adopted to modified RPC, and plain reactive powder concrete (PRPC), basalt fiber reactive powder concrete (BFRPC) and steel fiber reactive powder concrete (SFRPC) were prepared. The mechanical properties and freeze–thaw durability of BFRPC with different basalt fiber contents were tested and compared with PRPC and SFRPC to investigate the effects of basalt fiber contents and fiber type on the mechanical properties and freeze–thaw durability of RPC. Besides, the mass loss rate and compressive strength loss rate of RPC under two freeze–thaw conditions (fresh-water freeze–thaw and chloride-salt freeze–thaw) were tested to evaluate the effects of freeze–thaw conditions on the freeze–thaw durability of RPC. The experiment results showed that the mechanical properties and freeze–thaw resistance of RPC increased as the basalt fiber content increase. Compared with the fresh-water freeze–thaw cycle, the damage of the chloride-salt freeze–thaw cycle on RPC was great. Based on the freeze–thaw experiment results, it was found that SFRPC was sensitive to the corrosion of chloride salts and compared with the steel fiber, the improvement of basalt fiber on the freeze–thaw resistance of RPC was great.

scholarly journals Study on Long-Term Dynamic Mechanical Properties and Degradation Law of Sandstone under Freeze-Thaw Cycle

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Qingsong Pu ◽  
Junhong Huang ◽  
Fuling Zeng ◽  
Yi Luo ◽  
Xinping Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Air Pressure ◽  
Freeze Thaw ◽  
Dynamic Mechanical ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Dynamic Compressive Strength

This study is based on the tunnel-face slope engineering of Dongfeng tunnel in Shanxi section of China’s Shuozhou-Huanghua Railway. The sandstone specimens in the perennial freeze-thaw zone of the slope were collected to carry out freeze-thaw cycle static physical mechanics test and split Hopkinson pressure bar (SHPB) dynamic mechanical test. Thus, the damage process of sandstone under freeze-thaw cycle and impact load is studied. Also, the dynamic compressive strength and dynamic elastic modulus of sandstone are analysed under different loading strain rates and freeze-thaw cycle based on LS-DYNA, a dynamic finite element program. The results showed that the dynamic compressive strength of sandstone subjected to multiple freeze-thaw cycles under 0.04 MPa air pressure has a greater damage ratio than that under 0.055 MPa and 0.07 MPa air pressure, which was more likely to cause damage to slope sandstone than in actual engineering; the dynamic compressive strength and elastic modulus of sandstone decrease greatly within a certain range of freeze-thaw cycles and loading strain rate, leading to significant deterioration. When the freeze-thaw cycle exceeded 200 times and the strain rate was greater than 200 s−1, the physical and mechanical properties of sandstone gradually tended to be stable.

scholarly journals Experimental Study on the Durability of Alkali-Activated Slag Concrete after Freeze-Thaw Cycle

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Bin Chen ◽  
Jun Wang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Raw Material ◽  
Dynamic Elastic Modulus ◽  
Important Indicator ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Activated Slag ◽  
Alkali Activated

A freeze-thaw resistance is an important indicator of the durability of alkali-activated slag concrete, which causes structural failure when the performance is low, especially in severely cold areas. In this study, solid sodium aluminate and sodium silicate were used as composite alkaline activators, while slag was used as the raw material to prepare alkali-activated slag concrete, whose freeze-thaw resistance, as well as that of ordinary cement concrete, was experimentally studied by varying the freeze-thaw cycles. The effects of the mass, compressive strength, and dynamic elastic modulus of the sample were investigated by considering the influence of different water-to-slag ratios and slag contents, while the damage variables and model were also analyzed. The results showed that alkali-activated slag concrete had an excellent freeze-thaw resistance, which was significantly affected by the water-to-slag ratio and compressive strength; specifically, the higher the water-to-slag ratio, the lower the freeze-thaw resistance, and the higher the compressive strength, the better the freeze-thaw resistance. The freeze-thaw durability, microstructure, and damage mechanism were studied via microscopic analysis. When analyzed via the microstructure test, crack pores and microcracks with narrow spaces and large surface areas were generated under freeze-thaw damage conditions, but the dense hydration structure and high-bonding-strength hydration products led to a better freeze-thaw resistance. The damage model was established using compressive strength and relative dynamic elastic modulus as damage variables, and the attenuation exponential and accumulative damage power function model had a high accuracy, which could better reflect the freeze-thaw damage law and damage degree and predict the lifetime of alkali-activated slag concrete.

scholarly journals Frost Resistance Test Research on Hybrid Fiber Concrete Based on Range Analysis

2015 ◽  
Vol 9 (1) ◽  
pp. 292-297 ◽  
Author(s):  
Liu Faming ◽  
Zhao Lisha ◽  
Ma Jie
Keyword(s):  
Compressive Strength ◽  
Frost Resistance ◽  
Loss Rate ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Strength Loss ◽  
Hybrid Fiber ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Fiber Concrete

The research of single doped fiber concrete is relatively mature. But the research about different varieties and different geometry shape of hybrid fiber concrete was very poor. Across the research in theory, hybrid fiber concrete can improve the balance of fiber three-dimensional distribution and coordinating role of aggregate and fiber, improve the efficiency of toughening crack resistance. In this paper, through the orthogonal experiment design method for hybrid fiber reinforced concrete, the mass and compressive strength loss rate after 50 times, 75 times, 100 times freeze-thaw cycle had been studied. Use range analysis quantified the influence level of various factors on the mechanical properties. It was analyzed the hybrid fiber influence on improving the efficiency of toughening crack resistance and frost resistance. It is concluded that adding the fiber can enhance the performance of concrete frost resistance. Long steel fiber have great influence on compressive strength loss rate of hybrid fiber concrete, such as the compressive strength loss rate was reached 65.47% after 75 times freeze-thaw cycle. Short steel fiber have certain influence on mass loss of concrete which were after less freeze-thaw cycles. The influence of polypropylene fiber on concrete frost resistance increases significantly, the effect can reach 36.78% after 50 times of freeze-thaw cycle. The optimal combination of the hybrid fiber concrete ultimately determined was A2B2C3 (simultaneously mixed with 50kg/m3 short steel fiber and long steel fiber as well as 0.9kg/m polypropylene fiber). The addition of steel fiber and polypropylene fiber are both beneficial to increase the internal air content of concrete, strengthening the frost resistance of concrete. However, with the increase of dosage, the internal porosity of concrete is gradually increasing, the density is reduced, and, as a result, the corresponding increase of the compressive strength loss rate is also improved.

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