Experimental Study of Frost-Resistance Properties of Silica Fume Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1626-1629 ◽  
Author(s):  
Zhi Gang Yin ◽  
Jun Feng ◽  
Shu You Huang ◽  
Bing Fang Zhao

The frost resistance of low strength concrete is researched. In order to evaluate the effect of different content of silica fume on frost resistance,the quality of the cement 6%, 9%, 12% silica fume are respectively added into concrete. Freezing-thawing test results show that: the silica fume concrete has good frost resistance. Content of silica fume on concrete is not almost effect to quality loss rate. In 0-250 times of freezing-thawing cycle range, it is smaller that relative dynamic elastic modulus change rate. Relative dynamic elastic modulus of ordinary concrete decreases rapidly after 250 times of freezing-thawing cycle while dynamic elastic modulus decrease rate of the silica fume concrete tends to slow. The freezing -thawing cycles up to 350 times, silica fume concrete relative dynamic elastic modulus is 1.5 times that of ordinary concrete that show the silica fume concrete frost resistance is better than that of ordinary concrete.

2012 ◽  
Vol 509 ◽  
pp. 82-87
Author(s):  
Jin Bang Wang ◽  
Zong Hui Zhou

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.


2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang

. 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.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yushi Liu ◽  
Xiaoming Zhou ◽  
Chengbo Lv ◽  
Yingzi Yang ◽  
Tianan Liu

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.


2012 ◽  
Vol 174-177 ◽  
pp. 721-725 ◽  
Author(s):  
Ming Bao Gao ◽  
Yan Ru Zhao ◽  
Xiao Yan He

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.


This paper examines the impacts of substitution of reused concrete sand (RCS) with sands, on the new and hardened physiognomies of concrete. the property of RCS blended concrete was examined and likened with ordinary concrete of 40 MPa compression strength. the physiognomies of RCS concrete vary from ordinary concrete arranged with characteristic sand, as an outcome of the quality of connected mortar, old cement glue, and more fines. the outcomes demonstrate that the RCS concrete demonstrations tantamount workability in contrast with ordinary concrete. the mechanical physiognomies (compressive, flexure, split tensile and elastic modulus) of concrete developed with RCS was lower in compression to ordinary concrete however worthy up to 60percentage RCS in the blend. The drying shrinkage strain of 100percentage RCC mixed concrete at twenty-eight days was watched twice in compression to controlled concrete and it demonstrated more abrasion value in that comparison and furthermore concrete developed with 100 percent RCS indicated 41percentage and 11.3percentage lower in sorption value at ahead of schedule and later age organize individually in that examination.


2021 ◽  
Vol 10 (1) ◽  
pp. 1776-1788
Author(s):  
Yang Wen ◽  
Hui Sun ◽  
Shuaidong Hu ◽  
Guangmao Xu ◽  
Xiazhi Wu ◽  
...  

Abstract The goals of this paper are to study the frost resistance of steel slag concrete (SSC), research the damage mechanisms, and predict the service life of SSC in cold regions. First, the stability of steel slag (SS) was tested, and then SS samples with different treatment dosages were used as aggregates to replace natural aggregates of equal volumes in the preparation of C40 concrete. The microstructures of concrete and micro properties of cement hydration products were investigated in nanospace in this research. In addition, rapid frost resistance durability tests were carried out under laboratory conditions. The results revealed that the ordinary concrete (OC) exhibited a more serious damage phenomenon, and the mass loss and relative dynamic elastic modulus of OC were changed by 5.27 and 62.30%, respectively. However, with increases in the SS content, the losses in mass were lowered. Furthermore, the relative dynamic elastic modulus decreased less, and the frost resistance of the specimens was stronger. The range of mass loss rate was between 2.233 and 3.024%, and the relative dynamic elastic modulus range was between 74.92 and 91.09%. A quadratic function with a good fitting degree was selected to establish a freezing-thawing damage calculation model by taking the relative dynamic elastic modulus as the variable. Then, the freezing-thawing durability lifespan of concrete in the colder regions of northern China was successfully predicted by using the damage calculation model. The results of SSC20–60 showed the better frost resistance durability when the content of SS sand was 20% and the dosage of SS stone was 60%. Its frost resistance lifespan was more than twice that of OC, which demonstrated that SS as an aggregate could effectively improve the frost resistance lifespan of concrete to a certain extent.


2010 ◽  
Vol 168-170 ◽  
pp. 1010-1015 ◽  
Author(s):  
Wei Bo Huang ◽  
Ping Lu ◽  
Jing Zhang ◽  
Xin Mao Li

Coating protection becomes the primary and available method for the protection of marine concrete. Aliphatic polyurea is a new genre of polyurea. In the present study, the frost resistance property and adhesion property of 2 different aliphatic polyurea coated concretes under salt fog exposure were studied for the first time. The surface morphology and molecular structure of the coating under the salt fog exposure were investigated through SEM and FTIR. The investigations on the influence of the salt fog exposure to the PAE-t-HDI prepolymer-D2000H65 aliphatic polyurea (T3) coated concrete and T3 finishing coat/ MDI emulsion primer aliphatic polyurea (TM) coated concrete reported that after 300 days salt fog exposure, the relative dynamic elastic modulus of T3 and TM coated concrete were more than 85%, and their wet adhesion were 1.0 N/mm and 2.5N/mm respectively. SEM and FTIR researches showed that no obvious changes were observed in the surface morphology and structure of the coating after 200 days salt fog exposure. The results indicate that aliphatic polyurea coated concretes have favorable salt fog resistance, and are suitable for applying in marine concrete structures.


2011 ◽  
Vol 368-373 ◽  
pp. 2346-2350
Author(s):  
Yi Duo Zhang ◽  
Rong Gui Liu ◽  
Yu Chen ◽  
Kai Fu

Based on fatigue tests of pre-stressed concrete (PC) and ordinary concrete beams for 15 specimens after different times of freezing-thawing circle, the degradation process for the tested beams of the relative dynamic elastic modulus is conducted. The experimental study shows that the pre-stressing level and times of freezing-thawing circles are main influence factors to durability of test beams. The results of this study are useful for the exploration of the mechanism of the PC structure’s damage and the improvement of design theory concerning the durability of the PC structures.


2021 ◽  
Vol 14 (10) ◽  
Author(s):  
De-Gou Cai ◽  
Shao-Wei Wei ◽  
Yang-Sheng Ye ◽  
Qian-Li Zhang ◽  
Zhong-Guo Li ◽  
...  

AbstractA high-speed railway has high requirements for line smoothness, and uneven settlement control is the primary factor considered in the design and operation of the subgrade. The emergence of lightweight subgrade structures meets the needs of the development of the high-speed railway. As a kind of filling material with good performance, lightweight foam concrete can effectively reduce the load and excessive settlement of subgrade and effectively reduce the cost of foundation treatment. This paper studied the dynamic characteristics of lightweight foam concrete with different wet densities and water-bearing states under train loading. The effects of wet density and fly ash content on the compressibility, impermeability, and frost resistance of lightweight foam concrete were analyzed in detail. The results show that the lightweight foam concrete still has high residual strength after compression, which is about 60% of its peak strength. Under different mix ratios, the critical dynamic stress of the lightweight foam concrete is generally 0.2–0.3 times the unconfined compressive strength, and the dynamic elastic modulus increases with the increase of wet density and cyclic stress amplitude. With the fly ash content increasing, the volume water absorption of lightweight foam concrete decreases first and then increases, and the critical value of fly ash content is 40%. The frost resistance of lightweight foam concrete gradually increases with the increase of wet density, and the dynamic elastic modulus of the sample with 279 kg·m−3 density lost 41.1% after 20 freeze–thaw cycles. When the content of fly ash is 20%, the frost resistance of lightweight foam concrete is equivalent to that of pure cement.


2014 ◽  
Vol 936 ◽  
pp. 1419-1422
Author(s):  
Ai Lian Zhang ◽  
Lin Chun Zhang

This article studies the frost resistance of LYTAG concrete and ordinary concrete respectively used the RILEM recommended test method (CIF) about frost resistance of concrete. The results indicate that the single surface's frost resistance of Lytag concrete with mineral admixture is much better than normal density concrete's. And the rank of the single surface's frost resistance at 56 cycles of Lytag concrete with different mineral admixture is: silica fume and slag> silica fume and fly ash>slag and fly ash>silica fume>fly ash>slag. The important reasons why LYTAG concrete has good frost resistance is that the scope of blending interfacial transition zone of LYTAG concrete between aggregate ceramsite and cement stone was significantly smaller than ordinary concrete.


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