scholarly journals Characteristics of soil salt crust formed by mixing calcium chloride with sodium sulfate and the possibility of inhibiting wind-sand flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shenghui Li ◽  
Chengzhi Li ◽  
Xiaolei Fu

AbstractSoil salt crust can change the structure of aeolian soil and improve its resistance to wind erosion. Four ions (Na+, Ca2+, Cl−, and SO42−) with high contents in aeolian soil were selected for a salt crust experiment. The experiment set a variety of gradients of soil salt contents and salt mixing ratios of Na2SO4 and CaCl2. The physical properties of the salt crust were tested, and the wind erosion resistance of the salt crust was discussed. The results showed that the soil salt contents and salt mixing ratio influenced the resistance of the salt crust, especially in terms of its compressive strength and toughness. The former affected the compressive strength of the salt crust by changing the amount of cemented soil salt. The latter affected the kinds of crystals by changing the ion ratio, thus changing the structure of the salt crust and affecting its wind erosion resistance. The wind erosion resistance of the salt crust is complicated by the interaction between the soil salt content and salt mixing ratio. A multilayer crust can be formed in mixed salt, which has a strong wind erosion resistance. This result provides new findings on flowing sand soil and a new method for the treatment of flowing sand soil.

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744084 ◽  
Author(s):  
Xin Liu ◽  
Shengnian Tie

Searching for an economical and effective sand-fixing material and technology is of great importance in Northwest China. This paper described the use of a semihydrated gypsum-(CaSO4 ⋅ 1/2H2O-)based composite as a sand-fixing material. Its morphology and composition were characterized by SEM, and its water resistance, freezing–thawing resistance and wind erosion resistance were tested in the field. The results indicated that semihydrated gypsum-(CaSO4 ⋅ 1/2H2O-)based sand-fixing composite has good water resistance and water-holding capacity. Its strength is maintained at 1.42 MPa after 50 freezing and thawing cycles, and its wind erosion increases with increasing wind speed and slope. Its compressive strength starts to decrease after nine months of field tests with no change in appearance, but it still satisfies the requirements of fixation technology. This sand-fixing material should have wide application owing to its good weather resistance.


2011 ◽  
Vol 477 ◽  
pp. 290-295 ◽  
Author(s):  
Li Bo Bian ◽  
Shao Min Song

Considering large number production of the abandoned tyres and the question of the concrete with mixture of crumb rubber,the mainly task of this paper is to study the mechanical properties of different mixing ratio concrete with vary volume of crumb rubber. The results showed that the workability, apparent density, compressive strength, flexural strength and brittleness index decrease as the increase of crumb rubber. While the anti-crack performance and anti-fatigue performance can be improved. The wear-resistance properties are a little lower than common concrete.


2009 ◽  
Vol 620-622 ◽  
pp. 631-634
Author(s):  
Woo Keun Lee ◽  
Eun Zoo Park ◽  
Ji Hyeon Lee ◽  
Yeong Seok Yoo

In this work, inorganic paste was made from melting slag (MS) of MSWI ash and MSWI bottom ash (MBA) by geopolymer technique. Heavy metals such as Pb and Cu are highly contained in MBA. In the view of environmental protection and resource conservation, recycling of MSWI ash is desirable. MS and MBA were mixed to make inorganic paste. Compressive strength was measured to evaluate the characteristics of inorganic paste after the period of 1, 3 and 7day. Compressive strength of almost 90 MPa was obtained at the mixing ratio of MS : MBA = 9 : 1. And the crystalloid and crystal structure was analyzed by FTIR and XRD. Korea Standard leaching Test (KSLT) is also used to evaluate the environmental safety of inorganic paste. The leached concentration of Pb and Cu were 0.44 ppm and 0.15 ppm, respectively. According to this result, heavy metals were safety immobilized and stabilized.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Adnan Güven ◽  
Ahmet Bilgil

Pumice, cements (CEM I- and CEM II-type), waste fly and bottom ashes (IFA, GBA, and BBA) supplied from international companies were used to produce lightweight building materials, and physical-mechanical properties of these materials were determined. Axial compressive strength (ACS) values were found above the standards of 4 and 8 MPa (Bims Concrete (BC) 40 and 80 kgf/cm2 class) for cemented (CEM I) pumice-based samples. On the contrary, the ACS values of the pumice-based cemented (CEM II) samples could not be reached to these standards. Best ACS results (compatible with BC80) from these cemented lightweight material samples produced with the ashes were found in 50% mixing ratio as 10.6, 13.2, and 20.5 MPa for BBA + CEM I, GBA + CEM II, and IFA + CEM I, respectively, and produced with pumice were found as 8.4 MPa (same value) for GBA + pumice + CEM II (in 25% mixing ratio), BBA + pumice + CEM I (in 100% mixing ratio), and pumice + IFA + CEM I (in 100% mixing ratio), respectively. According to the results, cemented ash-based lightweight building material produced with and without pumice could widely be used for constructive purposes. As a result of this study, an important input to the ecosystem has been provided using waste ashes, whose storage constitutes a problem.


2016 ◽  
Vol 78 (9-2) ◽  
Author(s):  
Hasan Mohd Faizal ◽  
M. Shafiq M. Nazri ◽  
Md. Mizanur Rahman ◽  
S. Syahrullail ◽  
Z. A. Latiff

High global energy demand scenario has driven towards transformation from sole dependence on fossil fuels to utilization of inexhaustible renewable energy sources such as hydro, biomass, solar and wind. Renewable energy sources are abundant in Malaysia, especially palm biomass residues that are produced during the oil extraction process of fresh fruit bunch. Therefore, it is inevitable to harness these bioenergy sources, in order to prevent waste accumulation at adjacent to palm mills. Briquetting of palm biomass such as empty fruit bunch (EFB) with polyethylene (PE) plastics waste addition is expected not only could maximize the utilization of energy resources, but also could become as a potential solution for residue and municipal plastics waste disposal. In the present study, the physical and combustion properties of palm biomass briquettes that contain novel mixture of pulverized EFB and PE plastics waste were investigated experimentally. The briquettes were produced with different mixing ratio of EFB and PE plastics (weight ratios of 95:5, 90:10 and 85:15), under various heating temperatures (130-190 ) and at constant compaction pressure of 7 MPa. Based on the results, it can be said that heating temperature plays a significant role in affecting physical properties such as relaxed density and compressive strength. The values of relaxed density and compressive strength are within the range of 1100 to 1300 kg/m3 and 0.8 to 1.2 MPa, respectively. Meanwhile, mixing ratio does affect relaxed density and gross calorific value. All values of gross calorific (17900 to 21000 kJ/kg) and moisture content (7% to 9%) are found to fulfill the requirement for commercialization as stated by DIN51731 (gross calorific value>17500 kJ/kg and moisture content<10%). Even though the values of ash content (3% to 4%) exceed the limitation as stated by the standard (<0.7%), it is still considered very competitive if compared to the commonly used local briquette that contains mesocarp fibre and shell (5.8%). Finally, it can be concluded that the best quality of briquette can be achieved when highest composition of PE plastics (weight percentage of 15%) is used and the briquetting process is performed at the highest temperature (190 ).  


2012 ◽  
Vol 32 (11) ◽  
pp. 3449-3459 ◽  
Author(s):  
何新林 HE Xinlin ◽  
陈书飞 CHEN Shufei ◽  
王振华 WANG Zhenhua ◽  
贾文俊 JIA Wenjun ◽  
何建斌 HE Jianbin ◽  
...  

2014 ◽  
Vol 804 ◽  
pp. 15-18
Author(s):  
Yeong Geum Son ◽  
Woo Keun Lee

In this work, pastes were prepared from slag and MSWI bottom ash by geopolymer technique. And its physical property was evaluated with mixing ratio of sodium silicate and potassium silicate. The amounts of leaching products, such as silica, alumina and calcium ions were changed for mixing ratio of raw materials. The compressive strength was increased with the increment of leaching amount of silica, alumina and calcium ions.


2014 ◽  
Vol 584-586 ◽  
pp. 1563-1567 ◽  
Author(s):  
Bang Hua Xie ◽  
Chun Tao Wang ◽  
Min Fu Fu ◽  
Yun Sheng Li

In order to investigate the effect of Nano-SiO2 on the compressive strength of concrete, the paper studies the effect of different mixing ratios (0%~3%) on the compressive strength, and the effect of age on the compressive strength of nano-concrete. Research shows that the incorporation of Nano-SiO2 increased the compressive strength of concrete: it increases slowly with the mixing ratio 0%~1%; the growth rate is declining when the mixing ratio is 1.5%~3%; the optimal mixing ratio is 1.0~1.5%, which can replace 3.33~10% of cement.


2017 ◽  
Vol 11 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Huaxin Liu ◽  
Jianwei Yang ◽  
Xiangqing Kong ◽  
Xuxu Xue

In order to study the basic mechanical properties of basalt fiber reinforced recycled aggregate concrete, the concrete mix ratio, the length and the volume mixing ratio of chopped basalt fiber yarn are designed for changing factors. A total of 324 specimens have been completed for this investigation. The compressive strength, splitting tensile strength, elastic modulus and axial compressive strength of basalt fiber recycled concrete have carried on the experimental study and theoretical analysis as 81 specimens, respectively. In all specimens, coarse aggregate were replaced by recycled aggregate with a replacement rate of 100%. Experimental results show that the failure process and failure pattern of basalt fiber recycled concrete and ordinary concrete are similar; With the improvement of concrete strength grade; When the volume mixing ratio of chopped basalt fiber yarn is 0.2%, the mechanic performance can effectively improve, and the length of chopped basalt fiber has less effect on the mechanical indexes; The conversion relation between common concrete mechanics index is no longer suitable for basalt fiber recycled concrete, new conversion formulas for basalt fiber recycled concrete between the mechanics index were presented through fitting experimental data.


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