Laboratory Experimental Research on Mix Ratio Test of Cement Soil

2013 ◽  
Vol 438-439 ◽  
pp. 197-201
Author(s):  
Xian Hua Yao ◽  
Peng Li ◽  
Jun Feng Guan

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.

2020 ◽  
Vol 12 (1) ◽  
pp. 39-52
Author(s):  
Jair de Jesús Arrieta Baldovino ◽  
Ronaldo Luis dos Santos Izzo

The Guabirotuba Formation is located over the sedimentary basin of the city of Curitiba (Brazil). The gray layer of the Formation extends from 1 to 50 m deep. Although it is the most characteristic layer of the Formation, there are no studies of stabilization of these soils for urban paving purposes inthe city. Thus, this paper presents an experimental study of the stabilization of gray silt soil with Portland cement (PC) using cure times (t) of 7, 14, and 28 days. Cement contents (C) of 3, 5, 7, and 9% in relation to soil dry mass were used. After cure times, unconfined compressive strength (qu) and durability tests were performed using wet/dry cycles (W/D). The results show an increase of quwith increasing cement content, increasing molding density and increasing curing time. In addition, the durability of the mixtures increased when more cement was added. It was found that the values of quare dependent on the semi-empirical porosity/cement ratio (η/Civ). Finally, 5% is the minimum cement content for using the soil in paving purposes.


2019 ◽  
Vol 2 (2) ◽  
pp. 126-136
Author(s):  
M.I Retno Susilorini ◽  
Budi Eko Afrianto ◽  
Ary Suryo Wibowo

Concrete building safety of fire is better than other building materials such as wood, plastic, and steel,because it is incombustible and emitting no toxic fumes during high temperature exposure. However,the deterioration of concrete because of high temperature exposure will reduce the concrete strength.Mechanical properties such as compressive strength and modulus of elasticity are absolutely corruptedduring and after the heating process. This paper aims to investigate mechanical properties of concrete(especially compressive strength and modulus of elasticity) with various water-cement ratio afterconcrete suffered by high temperature exposure of 500oC.This research conducted experimental method and analytical method. The experimental methodproduced concrete specimens with specifications: (1) specimen’s dimension is 150 mm x 300 mmconcrete cylinder; (2) compressive strength design, f’c = 22.5 MPa; (3) water-cement ratio variation =0.4, 0.5, and 0.6. All specimens are cured in water for 28 days. Some specimens were heated for 1hour with high temperature of 500oC in huge furnace, and the others that become specimen-controlwere unheated. All specimens, heated and unheated, were evaluated by compressive test.Experimental data was analyzed to get compressive strength and modulus of elasticity values. Theanalytical method aims to calculate modulus of elasticity of concrete from some codes and to verifythe experimental results. The modulus elasticity of concrete is calculated by 3 expressions: (1) SNI03-2847-1992 (which is the same as ACI 318-99 section 8.5.1), (2) ACI 318-95 section 8.5.1, and (3)CEB-FIP Model Code 1990 Section 2.1.4.2.The experimental and analytical results found that: (1) The unheated specimens with water-cementratio of 0.4 have the greatest value of compressive strength, while the unheated specimens with watercementratio of 0.5 gets the greatest value of modulus of elasticity. The greatest value of compressivestrength of heated specimens provided by specimens with water-cement ratio of 0.5, while the heatedspecimens with water-cement ratio of 0.4 gets the greatest value of modulus of elasticity, (2) Allheated specimens lose their strength at high temperature of 500oC, (3) The analytical result shows thatmodulus of elasticity calculated by expression III has greater values compares to expression I and II,but there is only little difference value among those expressions, and (4)The variation of water-cementratio of 0.5 becomes the optimum value.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247599
Author(s):  
Yingjun Jiang ◽  
Jiangtao Fan ◽  
Yong Yi ◽  
Tian Tian ◽  
Kejia Yuan ◽  
...  

The vertical vibration compaction method (VVCM), heavy compaction method and static pressure method were used to form phyllite specimens with different degrees of weathering. The influence of cement content, compactness, and compaction method on the mechanical properties of phyllite was studied. The mechanical properties of phyllite was evaluated in terms of unconfined compressive strength (Rc) and modulus of resilience (Ec). Further, test roads were paved along an expressway in China to demonstrate the feasibility of the highly weathered phyllite improvement technology. Results show that unweathered phyllite can be used as subgrade filler. In spite of increasing compactness, phyllite with a higher degree of weathering cannot meet the requirements for subgrade filler. With increasing cement content, Rc and Ec of the improved phyllite increases linearly. Rc and Ec increase by at least 15% and 17%, respectively, for every 1% increase in cement content and by at least 10% and 6%, respectively, for every 1% increase in compactness. The higher the degree of weathering of phyllite, the greater the degree of improvement of its mechanical properties.


2011 ◽  
Vol 250-253 ◽  
pp. 788-794
Author(s):  
Shu Lin Zhan ◽  
Shu Sen Gao ◽  
Jun Ying Lai

In order to study the influence of modified polypropylene (PP) fiber on the physical and mechanical properties of curing sludge, the same amount of cement and different content of polypropylene fiber were mixed into the sludge. Unconfined compressive strength tests, water content tests and shear strength tests were carried out on different specimens with different curing time. The results show that the sludge curing effect is markedly improved by the addition of the polypropylene fiber. As to the curing sludge with the same curing time, when the content of the polypropylene fiber increases, the unconfined compressive strength and the cohesive strength greatly increase, and the internal frictional angle decreases.


Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Zhenkun Hou ◽  
Mengxiong Tang ◽  
Shihua Liang ◽  
Yi Zhu

The physical and mechanical properties of grouting materials greatly affect the friction resistance and the bearing performance of a non-soil-squeezing PHC pipe pile. Orthogonal tests for four factors at five levels were carried out to optimize the proportion of the water–cement mixture by using Portland cement as a raw material and a water-reducing agent, expansion agent and early-strength agent as additives. The following conclusions were obtained: (1) Both the water–cement ratio and the dosage of water-reducing agent are positively correlated with the fluidity of the water–cement mixture and have the greatest influence on the fluidity, followed by the expansion agent and early-strength agent. The saturation point of the water-reducing agent is 1.5%. (2) The strength of the grouting body decreases linearly with the increase of the water–cement ratio, and the dosage of the water-reducing agent has no obvious effect on the strength. As the dosage of expansion agent increases, the strength of the grouting body decreases rapidly. The expansion agent mainly plays a key role in the middle and late stages of the hardening process of the slurry. Early-strength agents have a greater impact on the early strength, but less on the later strength. When the slurry is solidified for 3 h, the early-strength agent has the greatest impact on the strength with an optimal dosage of 5%. (3) The volume of the grouting body has an inverse relationship with the water–cement ratio, and the optimal amount of expansion agent is 12%. The incorporation of an expansion agent makes the volume increase of the grouting body exceed the volume shrinkage ratio caused by the hardening of the grouting body with a curing time of more than 3 days, ensuring a slight increase in the volume of the grouting body. After 3 days, even though the effect of the expansion agent is gradually weakened, it can still ensure that the volume of the grouting body does not shrink. With the increase of the amount of water-reducing agent, the volume of the grouting body gradually decreases. When the amount of water-reducing agent exceeds 1.5%, the volume of the grouting body no longer decreases. (4) The early-strength agent has almost no effect on the volume of the grouting body. When the curing time is 3 h, the water–cement ratio has the greatest influence on the volume of the grouting body, followed by the water-reducing agent, and, finally, the expansion agent. After 3 h, the water–cement ratio still has the greatest influence, and the influence of the expansion agent gradually exceeds that of the water-reducing agent. The water-reducing agent mainly affects the volume of the grouting body in the water separation stage, and the expansion agent mainly plays a role in the middle and late stages of the slurry solidification. After optimized ratio analysis, the fluidity of the water–cement mixture can be improved, the volume shrinkage ratio rate can be lowered and the early strength can be increased.


Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 922
Author(s):  
Jiajian Li ◽  
Erol Yilmaz ◽  
Shuai Cao

Understanding the flow process of cemented tailings backfill (CTB) is important for successful pumping into underground stopes. This study examines the effects of solid content (SC), cement/tailings (c/t) ratio, and curing time (CT) on rheological and mechanical properties of CTB mixes. The slurry concentration of the mixes was 65, 67, and 69 wt. %, with c/t ratios ranging from 1:4 to 1:20. Unconfined compressive strength (UCS) tests were performed on hardened CTB mixes after curing 3, 7, and 28 days. The rheological properties of CTB slurries are mainly related to SC. The yield stress and viscosity of fresh mixes increase with increasing SC, but the pipeline resistance loss (PRL) also increases with increasing SC. According to the analysis of variance, the SC and flow rate are the most significant parameters which greatly affect the PRL performance. The c/t and CT parameters are the most significant parameters for affecting the shrinkage rate. The findings offer a reference for theoretical optimization for mine filling systems of similar type.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zhiguo Cao ◽  
Lian Xiang ◽  
Erxing Peng ◽  
Kai Li

Geotechnical applications based on soil resistivity measurement are becoming more popular in recent years. In order to explore the potential application of the electrical resistivity method in stabilization/solidification of contaminated soils, two kinds of lead-contaminated soils stabilized with cement were prepared, and the electrical resistivity and unconfined compressive strength of specimens after curing for various periods were measured. The test results show that a high lead content leads to a low value of electrical resistivity of cement-stabilized soils, and increasing cement content and curing time result in a significant increase in electrical resistivity. The reduction in porosity and degree of saturation, as a result of the cement hydration process, leads to an increase in electrical resistivity. The ratio of porosity-lead content/cement content-curing time, combining together the effect of lead content, cement content, curing time, and porosity on electrical resistivity of stabilized soils, can be used as a fundamental parameter to assess electrical resistivity of cement-stabilized lead-contaminated soils. Archie’s law can be extended to apply to cement-stabilized lead-contaminated soils by using this ratio, replacing the porosity. The new resistivity formula obtained in this paper is just empirical. There is a power function correlation between unconfined compressive strength and electrical resistivity of lead-contaminated soils stabilized with cement. Electrical resistivity measurement can be used as an economical and time-effective method to assess the quality of cement-stabilized lead-contaminated soils in practice.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Son Bui Truong ◽  
Nu Nguyen Thi ◽  
Duong Nguyen Thanh

Soft soil is widely distributed in Vietnam, especially in the coastal area. In engineering practice, soft soil cannot be used to build any construction and needs to be improved or treated before building construction. In addition, Vietnam has many pig-iron or thermal power plants, which annually produce a huge amount of granulated blast furnace slag (GBFS). Thus, the use of this material for soft soil improvement needs to be considered. This paper presents experimental results on the unconfined compressive strength (UCS) of three Vietnam’s soft soils treated with Portland cement and Portland cement with ground granulated blast furnace slag (GGBFS). Binder dosage used in this study is 250, 300, and 350 kg/m3 with the three different water/cement ratios of 0.8, 0.9, and 1.0, respectively. The research results showed that the UCS of soil-cement mixtures depends on soil type, water/cement ratio, cement type, and binder content. Accordingly, the unconfined compressive strength increased with the increase of binder contents, the decrease of the natural water content of soft soil, water/cement ratios, and clay content. The highest value of UCS of treated soils was found for the soil at Site II with the Portland cement content, cement GGBFS, and water/cement ratio of 873 kg/m3, 2355 kg/m3, and 0.8, respectively. Besides, for all the three soils and two binder types, the water/cement ratio of 0.8 was found to be suitable to reach the highest UCS values of treated soil. The research results also showed that the UCS of treated soil with cement GGBFS was higher than that of treated soil with Portland cement. This indicated the effectiveness of the use of Portland cement with GGBFS in soft soil improvement. There is great potential for reducing the environmental problems regarding the waste materials from pig-iron plants in Vietnam and the construction cost as well.


2014 ◽  
Vol 912-914 ◽  
pp. 131-135
Author(s):  
Xiang Ping Fu ◽  
Xiao Xue Liu ◽  
Yi Ze Sun ◽  
Pei Huang ◽  
Yu Chen Li ◽  
...  

The experiment studies how the freeze-thaw cycles influence concrete compressive strength and elasticity modulus with different water-cement ratio under the air-entraining agent and zero of that value respectively. It can be found that modulus of elasticity and compressive strength of the concrete specimen reduced significantly when there is air-entraining agent; the durability of freeze-thaw resistance, however, makes great improvement; as the cement increases, both of them improves effectively. Through the comparison of concrete compressive strength and elastic modulus with different water-cement ratio and air-entraining agent, the optimal water-cement ratio and air-entraining agent were determined. The results of experiment can be used in concrete engineering design in severe cold area.


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