Influence of Curing Pressure on Unconfined Compressive Strength of Cemented Clay

2018 ◽  
Vol 928 ◽  
pp. 263-268 ◽  
Author(s):  
Anuchit Uchaipichat
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Soft Clay ◽  
Peak Stress ◽  
Confining Pressure ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Soil Cement ◽  
Curing Pressure

The soil-cement columns are generally installed and cured in the soft clay layers under confining pressure. The strength of the soil-cement columns may be influenced by confining pressure during curing period. In this study, the main objective was to study the influence of curing pressure on unconfined compressive strength of cemented clay. A series of unconfined compression tests was performed on a cement admixed clay sample cured under pressure values of 0 kPa (atmospheric pressure), 25kPa, 50kPa and 100 kPa using a typical unconfined compression equipment. The test samples with values of cement content of 0.5, 1.0 and 2.0 percent were cured for 28 days.The stress-strain curves obtained from all tests show a peak value of stress. The unconfined compressive strength or peak stress obviously increased with increasing cement content for all curing pressure conditions. It can be observed that the strength of samples gradually increased with curing pressure for cement content of 0.5 percent. For cement contents of 1.0 and 2.0 percent, the strengths of samples cured under pressures of 25 kPa dramatically increased from the strength of samples cured without pressure (0 kPa), however, the strengths of samples for curing pressures of 25, 50 and 100 kPa were not clearly different.

Experimental Investigation on Unconfined Compressive Strength of Cemented Soils Admixed with Saturated GAC

2021 ◽  
Vol 1042 ◽  
pp. 145-150
Author(s):  
Anuchit Uchaipichat
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Unit Weight ◽  
Compression Tests ◽  
Compacted Soil ◽  
Curing Period ◽  
Soil Cement ◽  
Proctor Test ◽  
Cemented Soils

This research investigated the compressive strength of cemented soils admixed with saturated granular activated carbon (GAC). The saturated GAC was obtained from the water filtration system. A series of unconfined compressive strength was performed on both compacted soil-cement specimens and compacted soil-GAC-cement specimens with GAC content of 30 percent. All specimens were prepared by compaction with energy equivalent to the modified Proctor test. The results from modified Proctor tests showed that the maximum dry unit weight and the optimum moisture content of soil-GAC sample was less than those of soil sample. From the unconfined compression tests, there was tiny development of strength for both types of specimens with cement content of 1 percent throughout the curing period of 28 days. For both types of specimens with cement content of 2 and 3 percent, the significant development of strength occurred after curing for 3 days. The strength of specimens typically increased with increasing cement content. Generally, the strength of compacted soil-GAC-cement specimens was less than that of compacted soil- cement specimens. It was also observed that the relationships between normalized compressive strength ratio and curing period was unique for the specimens with the same cement content.

Experimental study on strength of cement stabilized clay

2005 ◽  
Vol 3 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Woo‐Sik Kim ◽  
Nguyen Minh Tam ◽  
Du‐Hwoe Jung
Keyword(s):  
Compressive Strength ◽  
Soil Type ◽  
Unconfined Compressive Strength ◽  
Weight Ratio ◽  
Dry Weight ◽  
Strength Characteristics ◽  
Curing Time ◽  
Compression Tests ◽  
Soil Cement ◽  
Mixing Method

This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.

scholarly journals The Effect of Polymer-Cement Stabilization on the Unconfined Compressive Strength of Liquefiable Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Ateş
Keyword(s):  
Compressive Strength ◽  
Compression Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Sandy Soils ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Unconfined Compression Strength ◽  
Compression Tests ◽  
Unconfined Compression

Soil stabilization has been widely used as an alternative to substitute the lack of suitable material on site. The use of nontraditional chemical stabilizers in soil improvement is growing daily. In this study a laboratory experiment was conducted to evaluate the effects of waterborne polymer on unconfined compression strength and to study the effect of cement grout on pre-venting of liquefiable sandy soils. The laboratory tests were performed including grain size of sandy soil, unit weight, ultrasonic pulse velocity, and unconfined compressive strength test. The sand and various amounts of polymer (1%, 2%, 3%, and 4%) and cement (10%, 20%, 30%, and 40%) were mixed with all of them into dough using mechanical kneader in laboratory conditions. Grouting experiment is performed with a cylindrical mould of  mm. The samples were subjected to unconfined compression tests to determine their strength after 7 and 14 days of curing. The results of the tests indicated that the waterborne polymer significantly improved the unconfined compression strength of sandy soils which have susceptibility of liquefaction.

Studi Pengaruh Abu Batu Bata terhadap SifatFisik dan Mekanik Lempung Terstabilisasi Kapur dari Kecamatan Tenayan Raya

2021 ◽  
pp. 17-23
Author(s):  
Soewignjo Agus Nugroho ◽  
Ferry Fatnanta ◽  
Giri Prayoga
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Moisture Content ◽  
Compression Strength ◽  
Unconfined Compressive Strength ◽  
Soft Clay ◽  
Setup Time ◽  
Unconfined Compression Strength ◽  
Unconfined Compression ◽  
Optimal Moisture Content

Tenayan Raya Subdistrict is an area that has a thickness of soft clay layer. Some cases of building failure were cracks and tilts due to high shrinkage of soil. Nearby is also a brick home industry center, where ashes are produced from bricks burning. Soil Improvement of Tenayan-Raya's Clay and utilization of brick ash will be carried out in this research. This study aims to stabilize the soil with lime and utilize the brick ash to improve shear strength and bearing capacity of the soil. The study was conducted in the laboratory by making several combinations of content clay, lime, and Brick Ash (BA), for the soil mixture which will be added with 10% ash brick. The effect of curing and soaked will also be seen for its rising on soil properties of Unconfined Compression Strength, and CBR laboratories. The influence of water will also be reviewed on the dry side, optimal moisture content, and wet side. The test results show that the Soil has Low Plasticity soil type category CL-ML symbols, according to the Unified classification. Increasing of strength due to stabilization with lime is obtained in conditions of water in optimal moisture content, where the addition of lime is 10% and 10% brick ash, was produced to increase the maximum value of Unconfined Compression Strength and CBR laboratory value. Curing setup time and saturation (soaked) also had affect the value of Unconfined Compressive Strength and CBR laboratory test. At longer time for curing, shear strength will rise proved by the value of UCS Test andbearing capacity value also increase that can be seen of the laboratory CBR test. Curing will make the shrinkage of clay reduced, this can be proven from differences value of Unconfined Compressive strength test between samples with and without soaked, are relatively small. 

A Preliminary Study of Stabilizing Artificial Saline Sludge Using Compound Stabilizer

2012 ◽  
Vol 450-451 ◽  
pp. 343-347
Author(s):  
Xiao Ming Shen ◽  
Zhan Guo Li ◽  
Da Huo ◽  
Hai Yan Zhao
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Soil Samples ◽  
Hydration Products ◽  
Large Area ◽  
Soil Cement ◽  
Stabilized Soil ◽  
Alkaline Component ◽  
Preliminary Study

There is large-area saline sludge which should be stabilized in China. In this experiment, cementitious component (cement), alkaline component (Ca(OH)2) and expansive component (sulfuraluminate cement or gypsum) were used as compound stabilizer with different combinations to stabilize artificial saline sludge, then the unconfined compressive strength of stabilized soil samples was determined, and the hydration products of the stabilized soil were analyzed by XRD, the stabilizing mechanism and the required hydrate species of stabilized soil were preliminary explored. The results show that the unconfined compressive strength of stabilized soil increases gradually with the increase of the cement content; when partial cement replaced by right amount of CH, the strength reaches the maximum and higher than that of soil-cement; the use of sulfuraluminate cement plaster as expansive component for stabilizing saline sludge has a relatively good overall affect compared to the gypsum; possible reasons for these results were speculated at the same time.

scholarly journals Mechanical Properties of Furnace Slag and Coal Gangue Mixtures Stabilized by Cement and Fly Ash

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7103
Author(s):  
Hongbo Li ◽  
Hubiao Zhang ◽  
Pengfei Yan ◽  
Changyu Yan ◽  
Yufei Tong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Peak Stress ◽  
Coal Gangue ◽  
Replacement Rate ◽  
Splitting Strength ◽  
The Relationship

The mechanical properties and strength formation mechanism of cement–fly-ash-stabilized slag–coal gangue mixture were examined using an unconfined compressive strength test, splitting strength test, triaxial test, and scanning electron microscopy to solve the limitations of land occupation and environmental pollution that is caused by fly ash from the Xixia District thermal power plant in Yinchuan, slag from the Ningdong slag yard, and washed coal gangue. Its performance as a pavement base mixture on the road was investigated. The results demonstrated that as the slag replacement rate increased, the maximum water content increased while the maximum dry density decreased. The addition of slag reduced the unconfined compressive strength and splitting strength of the specimens; furthermore, the higher the slag substitution rate, the lower the unconfined compressive strength and splitting strength of the specimens. As the cement content increased, the specimen’s unconfined compressive strength increased. Based on the principle of considering the mechanical properties and economic concerns, the slag replacement rate in the actual construction should be ~50% and should not exceed 75%. Based on the relationship between the compressive strength and splitting strength of ordinary concrete, the relationship model between the unconfined compressive strength and splitting strength of cement–fly-ash-stabilized slag–coal gangue was established. The failure mode, stress–strain curve, peak stress, and failure criterion of these specimens were analyzed based on the triaxial test results, and the relationship formulas between the slag substitution rate, cement content, peak stress, and confining pressure were fitted. As per the SEM results, the mixture’s hydration products primarily included amorphous colloidal C-S-H, needle rod ettringite AFt, unhydrated cement clinker particles, and fly ash particles. The analysis of the mixture’s strength formation mechanism showed that the mixture’s strength was the comprehensive embodiment of all factors, such as the microaggregate effect, secondary hydration reaction, and material characteristics.

scholarly journals Effect of Polypropylene Fibre and Curing Period on Unconfined Compressive Strength of Cemented-Black Cotton Soil

2019 ◽  
Vol 9 (1) ◽  
pp. 7244-7250
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Polypropylene Fibre ◽  
Black Cotton Soil ◽  
Polypropylene Fibres ◽  
Maximum Enhancement ◽  
Cemented Soil ◽  
Curing Period ◽  
Soil Cement

This paper discussed the effect of polypropylene fibre and curing period on the unconfined compressive strength (UCS) of cemented-black cotton soil. Various combinations of polypropylene fibres and cement have been taken and the UCS values of the treated black cotton soil specimens were determined after 3, 7 and 28days of curing. The study divulged that the mixing of polypropylene fibre increases UCS of cemented-black cotton soil. The rise in strength depends on the curing period. The 28days strength is 50 to 90% more than the corresponding 3days strength. The maximum enhancement of UCS from 969 to 2431kPa is achieved by adding 1% polypropylene fibre in cemented-black cotton soil having 15% cement after a curing period of 28days. The UCS of cemented-soil with 5% cement content, (Cc) and 1% polypropylene fibre is 781kPa which corresponds to the UCS of cemented-black cotton soil with 12% cement alone after a curing period of 28days. Thus, polypropylene fibre might be an economical admixture to enhance the performance of soil-cement column stabilised black cotton soil.

Effect of unloading duration on unconfined compressive strength

1999 ◽  
Vol 36 (1) ◽  
pp. 166-172 ◽  
Author(s):  
M A Fam ◽  
M B Dusseault
Keyword(s):  
Compressive Strength ◽  
Pore Pressure ◽  
Unconfined Compressive Strength ◽  
Excess Pore Pressure ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Coefficient Of Consolidation ◽  
Unconfined Compression Test ◽  
Excess Pore

This note examines the effect of unloading duration on unconfined compression test results. Artificial clayey specimens were prepared using the slurry consolidation technique. Extracted specimens were loaded vertically under K0 conditions, and the load was kept constant until the end of primary consolidation. Specimens were unloaded and unconfined compression tests were carried out at different times after unloading. It is observed that the longer the unloading duration, the lower the measured unconfined strength. This behavior is attributed to the presence of negative excess pore pressure that dissipates with time, reducing the strength. Using the measured coefficient of consolidation, the degree of excess pore pressure dissipation and therefore the average mean effective stress near the failure zone can be calculated at the time of failure. Mohr circles are drawn tangential to the total shear envelope, using the calculated mean effective stresses. Reasonable agreement between predicted and measured unconfined compressive strengths has been observed, suggesting that consolidation theory can be adopted to assess the effect of unloading duration on unconfined compressive strength. Finally, engineering applications using a similar concept are briefly discussed.Key words: clays, unloading, consolidation, unconfined compression tests, triaxial tests.

scholarly journals The Role of Additives in Soil-Cement Subjected to Wetting-Drying Cycles

2021 ◽  
Vol 6 (3) ◽  
pp. 48
Author(s):  
Yulian Firmana Arifin ◽  
Eka Agustina ◽  
Fransius Andhi ◽  
Setianto Samingan Agus
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Dry Weight ◽  
Weight Basis ◽  
Type I ◽  
Central Kalimantan ◽  
Road Base ◽  
Soil Cement

This study aimed to explore the use of additives in soil–cement mixtures that have undergone a wetting-drying cycle. In total, two types of soil were used, granitic and lateritic, which are widely used in road base construction in the Katingan area, Central Kalimantan, Indonesia. The cement used was the ordinary Portland type I, while the additive utilized was for commercial purposes, and predominantly contained CaCl2. This research was conducted by testing the optimum cement content for each soil to determine the shear strength according to Indonesian standards (i.e., minimum Unconfined Compressive Strength of 2400 kPa). The optimum cement contents of granitic and lateritic soils were deduced to be 5.5% and 5% on a dry weight basis, respectively. The utilization of 0.8% additive resulted in a 0.5% reduction in the optimum cement content of granite-like soil. The results showed that the optimum additive content for granitic soil was higher than that without supplementation, while for lateritic, no changes occurred. The advantage of using supplements, however, was more pronounced in the samples when they had been subjected to wetting–drying cycles. Additionally, at the optimum additive level, the moisture content and soil-cement loss during wetting was always lower than without supplements.

scholarly journals Compression and Strain Predictive Models in Non-Structural Recycled Concretes Made from Construction and Demolition Wastes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3177
Author(s):  
Evelio Teijón-López-Zuazo ◽  
Jorge López-Rebollo ◽  
Luis Javier Sánchez-Aparicio ◽  
Roberto Garcia-Martín ◽  
Diego Gonzalez-Aguilera
Keyword(s):  
Compressive Strength ◽  
Predictive Models ◽  
Unconfined Compressive Strength ◽  
Image Correlation ◽  
Peak Strain ◽  
Compression Tests ◽  
Maximum Peak ◽  
3D Digital Image Correlation ◽  
Granulometric Analysis ◽  
Physical And Chemical

This work aims to investigate different predictive models for estimating the unconfined compressive strength and the maximum peak strain of non-structural recycled concretes made up by ceramic and concrete wastes. The extensive experimental campaign carried out during this research includes granulometric analysis, physical and chemical analysis, and compression tests along with the use of the 3D digital image correlation as a method to estimate the maximum peak strain. The results obtained show that it is possible to accurately estimate the unconfined compressive strength for both types of concretes, as well as the maximum peak strain of concretes made up by ceramic waste. The peak strain for mixtures with concrete waste shows lower correlation values.

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