scholarly journals Experimental study on the influence of temperature on compressive strength of non-spontaneous combustion coal gangue aggregate concrete

2021 ◽  
Vol 702 (1) ◽  
pp. 012056
Author(s):  
Suqin Yao ◽  
Wenhua Zha ◽  
Yue Yu
Critical Care ◽  
10.1186/cc174 ◽  
1998 ◽  
Vol 2 (Suppl 1) ◽  
pp. P044
Author(s):  
Ma Qing ◽  
MC Seghaye ◽  
J Vazquez ◽  
RG Grabitz ◽  
B Klosterhalfen ◽  
...  

2008 ◽  
Vol 385-387 ◽  
pp. 381-384 ◽  
Author(s):  
Wei Wang ◽  
Hua Ling ◽  
Xiao Ni Wang ◽  
Tian Xia ◽  
Da Zhi Wang ◽  
...  

With the increase in the use of recycled aggregate concrete (RAC), it is necessary to clearly understand its behavior and characteristics. In this paper, experimental study on compressive strength of RAC with same water/cement ratio is conducted. Firstly, influence of recycled coarse aggregate contents on cube compressive strength of RAC is studied. Secondly, experiment on time-dependent strength developing process of RAC is conducted with different solidification ages. Finally, based on above experimental investigations, empirical formula for compress strengths of RAC with different ages is presented. The result of this paper is helpful to theoretical analysis and practical engineering design of RAC structures.


2012 ◽  
Vol 174-177 ◽  
pp. 1277-1280 ◽  
Author(s):  
Hai Yong Cai ◽  
Min Zhang ◽  
Ling Bo Dang

Compressive strengths of recycled aggregate concrete(RAC) with different recycled aggregates(RA) replacement ratios at 7d, 28d, 60d ages are investigated respectively. Failure process and failure mode of RAC are analyzed, influences on compressive strength with same mix ratio and different RA replacement ratios are analyzed, and the reason is investigated in this paper. The experimental results indicate that compressive strength of recycled concrete at 28d age can reach the standard generally, it is feasible to mix concrete with recycled aggregates, compressive strength with 50% replacement ratio is relatively high.


2013 ◽  
Vol 690-693 ◽  
pp. 374-377 ◽  
Author(s):  
Yan Shi ◽  
Xiao Jun Li ◽  
Chang Qing Hu

In a certain reaction time, CO2 concentration and flow rate, the carbonation experiment was carried out about green pellets prepared by the ferrous dust and active lime with 15%, 20%, 25%, 30% CaO content ratio respectively. The conversion ratio, porosity and compressive strength of carbonation pellets were analyzed at 200°C, 400°C, 600°C, 800°C.The results show that, with the reaction temperature increasing, CaO conversion ratio of carbonation reaction and the compressive strength increased, and the porosity decreased significantly; when the reaction temperature is 800°C, the CaO conversion ratio of reaction with 25% CaO content pellet can reach 47.26%, these can make the carbonation pellet to achieve a better carbonation degree and quality.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1899-1902
Author(s):  
Yan Kun Zhang ◽  
Yu Cheng Wang ◽  
Xiao Long Wu

In this article, the flexural strength of combined aggregate concrete with four kinds of water-cement ratio (0.3,0.35.0.4, 0.45), and six ceramsite replace rate (0%, 20%, 40%, 60%, 80%, 60%) are studied with comprehensive test method. Experiment shows that the ceramsite replace rate of combined aggregate has greater influence on the flexural strength than the water-cement ratio. The flexural strength increases with the increasing of compressive strength, and the formula of the flexural strength and compressive strength of combined aggregate concrete is given.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yanlin Huang ◽  
An Zhou

In recent years, with the rapid development of the construction industry, the demand for natural river sand has become increasingly prominent. Development of alternatives to river sand has become an interesting direction for concrete research. In this paper, coal gangue was proposed to replace part of the river sand to produce coal gangue fine aggregate concrete, while waste polyethene terephthalate (PET) bottles were used as raw materials to make PET fibers to improve the mechanical properties of coal gangue fine aggregate concrete. There were two parts of the test conducted. In the first part, the compressive strength of the gangue fine aggregate concrete cube, splitting tensile strength, axial compressive strength, and static elastic modulus were studied when the substitution rate of coal gangue increased from 0% to 50%. Referring to the equation of the full stress-strain curve of plain concrete, the stress-strain constitutive equation of coal gangue fine aggregate concrete was analyzed and studied. By comparing with plain concrete, it was found that the coal gangue concrete with a replacement rate of 50% had higher compressive strength and tensile strength, but its brittleness was significantly greater than that of plain concrete in the later stage. In the second part, by studying the effect of different PET fiber content on the mechanical properties of coal gangue fine aggregate concrete with a replacement rate of 50%, it was found that when the addition of PET fiber was 0.1% and 0.3%, not only were compressive strength, splitting tensile strength, static elastic modulus, and flexural strength of the gangue fine aggregate concrete effectively improved but also the brittleness of concrete can be significantly reduced. The study found that after adding 0.3% PET fiber, the coal gangue fine aggregate concrete with a replacement rate of 50% has better mechanical properties and less brittleness.


Author(s):  
Zhenxia Li ◽  
Tengteng Guo ◽  
Yuan Zhao Chen ◽  
Xu Zhao ◽  
Yanyan Chen ◽  
...  

Abstract In order to solve the environmental pollution of coal gangue and the shortage of aggregate resources in road engineering, waste coal gangue is used as road base material instead of natural stone materials. Through physical, mechanical, chemical and activity tests of coal gangue aggregate, the optimal gradation composition of unconfined compressive strength was determined. Through unconfined compressive strength, indirect tensile strength, flexural tensile strength, freeze-thaw and dry shrinkage tests, the influence of cement content on road performance of cement stabilized coal gangue mixture was studied. By means of SEM, ICP AES, XRD and optical digital microscope, the difference between spontaneous combustion coal gangue and Unspontaneous combustion coal gangue was analyzed, the microstructure of cement stabilized coal gangue mixture was characterized, and the strength formation mechanism of mixture was explored. The results show that Spontaneous combustion coal gangue has higher activity than Unspontaneous combustion coal gangue.Based on the selected optimal allocation(BNS:SNS:SSC =71.26:9.41:18.8),The mixture of 4% cement dosage can not only meet the requirement of early strength 4.16 MPa, but also show an efficient strength growth rate of 36.10%, showing the optimum mechanical properties. The total shrinkage coefficient of cement stabilized coal gangue mixture with 4% cement dosage is 1.12×10-2, which shows that the dry shrinkage resistance is the best. With the increase of time, hydration degree is gradually deepened, and gelled substance is more tightly bonded to aggregates. There is no obvious gap between aggregates, and the integrity of the mixture is enhanced, which can show better road performance. Ca (OH)2, a cement hydration product in cement stabilized coal gangue mixture, takes place pozzolana reaction with active SiO2 and Al2O3 in coal gangue to produce gismondine, which is beneficial to the global strength and the bond quality of the mixture.


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