Study on Curing Agent of Chemical Modification on Dredged Soil

2014 ◽  
Vol 507 ◽  
pp. 395-400
Author(s):  
Xia Zhen Zhang ◽  
Xia Hong Zhang ◽  
Jing Xu Ni ◽  
Jie Zhuang

Large amount of dredged silt has been produced in the construction of water conservancy projects and oceanographic projects in China every year. Solidification and modification of dredging silt, to transfer it to good geotechnical materials, will be significant benefits on the sustainable development of the society. The curing effect of dredging soil isnt good if selecting cement as the single main curing agent. In this paper, the industrial steel slag and waste slag were chosen as the main curing agent and matching with cement and alkali activator, such as water glass, gypsum and sulfate. The help curing agent dosage range has been determined by single doped tests. Then the best ratio of GKCS curing agent has been determined through orthogonal tests. The research shows that the unconfined compressive strength can be achieved 5905kPa after using GKCS curing agent modified dredged soil.

2014 ◽  
Vol 1030-1032 ◽  
pp. 860-863
Author(s):  
Jing Wei Wang ◽  
Wen Pan ◽  
Zhuo Yin Jiang

The Dian Lake Peat soil is studied as the research object in this paper, through the strengthening treatment by adding the cement and some suitable additives as well as a certain amount of waste residue, the compressive strength are taken into consideration in comparison in the different curing composition and other factors in performance of solidified soil. And it importantly discussed the applicability of curing agent and different variables (cement, the formula of curing agent, construction waste, age) in the incremental changes of unconfined compressive strength of curing peat soil.


2020 ◽  
Vol 26 (7) ◽  
pp. 145-157
Author(s):  
Zozk Kawa Abdalqadir ◽  
Nihad Bahaaldeen Salih ◽  
Soran Jabbar Hama Salih

The clayey soils have the capability to swell and shrink with the variation in moisture content. Soil stabilization is a well-known technique, which is implemented to improve the geotechnical properties of soils. The massive quantities of waste materials are resulting from modern industry methods create disposal hazards in addition to environmental problems. The steel industry has a waste that can be used with low strength and weak engineering properties soils. This study is carried out to evaluate the effect of steel slag (SS) as a by-product of the geotechnical properties of clayey soil. A series of laboratory tests were conducted on natural and stabilized soils. SS was added by 0, 2.5, 5, 10, 15, and 20% to the soil. The conducted tests are consistency limits, specific gravity, hydrometer analysis, modified Proctor compaction, swelling pressure, swelling percent, unconfined compressive strength, and California Bearing Ratio (Soaked CBR). The results showed that the values of liquid limit, plasticity index, optimum moisture content, swelling pressure, and swelling percent were decreased when stabilized the soil. However, the values of maximum dry density, unconfined compressive strength, and California bearing ratio were increased with the addition of steel slag with various percentages to the clayey soil samples. The steel slag was found to be successfully improving the geotechnical properties of clayey soils.


2012 ◽  
Vol 174-177 ◽  
pp. 676-680
Author(s):  
Fang Xu ◽  
Ming Kai Zhou ◽  
Jian Ping Chen

The unconfined compressive strength is used to be the valuation index, the mechanical performance of three kinds of new road base material, which are fly ash stabilized steel slag sand (FA-SS for short), lime and fly ash stabilized steel slag sand (L-FA-SS for short), cement and fly ash stabilized steel slag sand(C-FA-SS for short), are studied in this paper. The results show that the unconfined compressive strength performance of FA-SS is similar to L-FA-SS, and it can meet the highest strength when the ratio of steel slag to fly ash is 1:1~2:1. When the ratio of fly ash to the steel slag is 10:90, it is good to use cement stabilizing. Comparing the new road base materials with the traditional road base material, the former has better strength performance and economy function advantage.


2015 ◽  
Vol 744-746 ◽  
pp. 628-631
Author(s):  
Yi Xiang Chen ◽  
Kai Xi An ◽  
Ke Xin Zhou ◽  
Chen Hao Xu

In order to reveal the effect of type of admixture and its content on the strength of stabilized soil, this paper uses the sludge as raw soil and cement, fly ash as curing agent, and analyzes the strength characteristics of samples mixed stabilized according to certain content. Using the unconfined compressive strength test, the compressive strength of the samples is tested. The effect of curing agent type and its content on the compressive strength is investigated. From the experimental results, it can be seen that the content of cement and fly ash has much effect on the strength. The conclusions obtained can have some conference values on the foundation treatment and reuse of waste resources utilization.


2014 ◽  
Vol 1030-1032 ◽  
pp. 912-915
Author(s):  
Jing Wei Wang ◽  
Wen Pan ◽  
Zhuo Yin Jiang

This article discussed the applicability of the curing agent, the growth and change of the peat soil curing unconfined compressive strength and under the different variables (such as cement, curing agent formula, construction waste, age). We get the strength increase model by analyzing the results of peat soil solidification formula experiment. Regress equation about the cement dosage, curing agent, content of construction waste residue, age and principal component values was built by using the regression analysis.


2014 ◽  
Vol 936 ◽  
pp. 1382-1386
Author(s):  
Guo Cai Wang ◽  
Lin Chun Yu ◽  
Ling Sha

In order to study the inorganic composite curing agents of lime, gypsum, fly ash on the strength properties of EPS lightweight soil using recycled sludge, the unconfined compressive strength test and scanning electron microscope test are done to investigate the strength properties of EPS lightweight soil. The effect and scope of each curing agent is investigated and determined by means of single-doped unconfined compressive strength test, and the optimum proportion of the curing agent is further determined by the method of orthogonal unconfined compressive strength test, of which the stabilized effectiveness of the lightweight soil is compared with those only using cement as curing agent. Finally, the SEM test is done to study the microstructure and pore characteristics of the lightweight soil mixed with EPS adding with or without curing agent. The test results and curing agent can be used as conference when stabilizing soft soil and treatment of discarded clay.


2021 ◽  
Author(s):  
Xiaoyu An ◽  
Dianjun Zuo ◽  
Fei Wang ◽  
Chao Liang

Abstract The cement solidification/stabilization method of heavy metal contaminated soils has been promoted in engineering practice and applied on a large scale for site remediation, but it still reveals some scientific problems in the current complex and variable global extreme climate. To solve these problems and explore cement-based soil remediation technology, this study used the waste soda residue produced in large quantities in the "ammonia-soda process" as a composite additive, and established an innovative composite model of cement and soda residue by adding different ratios, which was applied to the remediation experiments of lead-contaminated soil. The innovative composite model solidification/stabilization of cement and soda residue for unconfined compressive strength and toxic leaching properties under different soil environmental conditions were investigated. Moreover, curing and leaching mechanisms are discussed, and future industrial practice was evaluated. The results showed that the addition of soda residue improved the early (20 days) unconfined compressive strength (UCS) of the composite curing agent for lead-contaminated soil by an average of 23.1% Mpa. When the percentage of soda residue composite was 40%, the UCS strength was 0.96 Mpa, which reached the maximum. The concentration of Pb2+ in the leachate of the cement-soda residue composite curing agent was greatly reduced (average 3.28 times) compared with that of a single cement in the same situation, with an average leached Pb2+ concentration of 1.87 mg·L-1. This indicates that the addition of alkali residue improved the curing effect. The curing mechanism was divided into four steps, mainly a complex physicochemical reaction between the cement-soda residue composite and soil particles. The leaching mechanism of cement-soda residue to aqueous solution is mainly the consumption of acid ions by alkaline substances. This study will provide scientific data to support potential lead-containing soil in site remediation technologies and future large-scale engineering applications.


2013 ◽  
Vol 405-408 ◽  
pp. 187-190 ◽  
Author(s):  
Lin Liu ◽  
Peng Fei Wu ◽  
Jin Diao Jiang

Improving MSW with help of the curing agent mixed with cement, fly ash and gypsum. The unconfined compressive strength test is carried out in different conservation age on the improved MSW; Analyzing the increasing mechanism of improved MSW combined with the method of SEM/EDS. Simulating acid alkaline environment with the liquor of H2SO4 and NaOH and studying the rule of acid and alkali erosion of improved materials. The result of experiment show that improved MSW which contain cement, fly ash and gypsum is better than it only mixed with cement; The strength of improved MSW mixed with cement is better than it only have cement ,and improve more in lye.


2019 ◽  
Vol 7 (9) ◽  
pp. 294 ◽  
Author(s):  
Shuai Yang ◽  
Wenbai Liu

In the South China Sea, calcareous sand, as a natural foundation, has the features of low mechanical properties, including its compressive strength. With the development of South China Sea islands, the problems of calcareous sand foundation are encountered in the process. However, the experience of traditional pile foundation engineering could not be applied to calcareous sand. In this study, different proportions of curing agents were added to calcareous sand to improve the compressive strength. The quantitative analysis of the relationship between the unconfined compressive strength and microstructure of solidified calcareous sand is discussed. The unconfined compressive strength was gauged from unconfined compressive strength tests. Microscopic images, acquired using a scanning electron microscope (SEM), were processed using the Image-Pro Plus (IPP) image processing software. The microscopic parameters, obtained using IPP, include the average equivalent particle size (Dp), the average equivalent aperture size (Db), and the plane pore ratio (e). This research demonstrates that the curing agent could improve the compressive strength, which has a relation with the three microstructure parameters. The curing agent, through hydration reaction, generates hydration products, i.e., calcium silicate hydrate, calcium hydroxide, and calcite crystals. They adhere to the surface of the particles or fill the space between the particles, which helps increase the compressive strength. In addition, there is a good linear relationship between the macroscopic mechanics and the microscopic parameters. Using the mathematical relation between the macroscopic and microscopic parameters, the correlation can be built for macro-microscopic research.


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