Experimental Study on Engineering Performance of Portland Cement Stabilization of Soil-Bentonite

2011 ◽  
Vol 179-180 ◽  
pp. 978-982
Author(s):  
Xiao Yong Li ◽  
Zhi Gang Zhang

Slurry trench cutoff walls, constructed using self-hardening cement-bentonite (SCB) are the most common form of in-ground vertical contaminant barrier in the world, and are increasingly being used in China. As a kind of vertical anti-seepage wall material, SCB slurry is requently used for the containment of contaminated groundwater and other envirofunental Protection Projeets abroad. Domestie applieation of cement-bentonite slurry walls is not extensive. The objective of this study was to evaluate the effect of water-cement ratio and cement content on the hydraulic behavior of SCB and soil–bentonite (SB) mixtures permeated with water. The experimental program included unconfined compression tests, expansion ratio tests and hydraulic conductivity tests. The test results indicated changes in hydraulic conductivity take place due to the variation of the water-cement ratio and permeant fluid. Cement is a main material in effecting the CSB strength of unconfined compression. Cement greatly influenced the CSB permeability coefficient. Addition of Portland cement to the SB mixtures increased their hydraulic conductivity when permeated with water. The hydraulic conductivity of the SCB specimens permeated with water was inversely related to the cement content.

2021 ◽  
Vol 9 (2) ◽  
pp. 106-109
Author(s):  
Fathelrahman M. Adam ◽  
Omer E. A. ◽  
Mohammed I. Ali ◽  
Salih E. M.

In this research, a study of using silica sand of a purity reaches 95% was done in order to know its effects on the strength of concrete when it used as an alternative to the normal sand by a different ratio of 25%, 50%, 75% and 100%. The study was done using Normal Portland Cement with a water/cement ratio of 0.52 and the mix design was done according to the British Standard Method. The ratio 1:1.5:3 was used for the different materials composed of the mix design. A reference mix design was used without containing any silica sand by means of 0% ratio of silica sand. Compression tests for the strength of concrete have been done for cubes of 7 days and 28 days age of curing and the results obtained appeared that the using of silica sand increases the concrete strength with reaching the peak at a ratio of 50% of silica sand where the strength was increased for the 7 days and 28 days by a ratio of 10% and 11% more than the strength of reference mix design respectively. Also, the study appears that the increase of silica sand by more than 50%, leads to the brittleness of concrete and this has been seen clearly when the ratio of silica sand reached 100% since the strength of concrete be down by 31% for 7 days and by 16% for the 28 days.  


2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.


2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.


2016 ◽  
Vol 711 ◽  
pp. 599-606
Author(s):  
Geert de Schutter

Deemed-to-satisfy durability requirements, as typically provided in code prescriptions (minimum cement content, maximum water cement ratio, minimum strength class) are now approaching their limits of applicability. With the implementation of new tailor-made binder types, including a multitude of powders (reactive and even non-reactive), the prescriptive parameters cement content and water/cement ratio become unclear and do not always correlate well with the real durability performance. While the equivalent concrete performance concept (ECPC) already offers a first way out of this debate, it still fundamentally maintains durability requirements at a deemed-to-satisfy level, as the new binder type needs to be experimentally calibrated relative to a standard solution. A more fundamental solution needs to consider the absolute durability performance of the concrete applied in the real structure. This performance needs to be evaluated in laboratory conditions (potential performance) as well as on the final structure (as-built performance). However, although straightforward in principle, the quest for absolute durability performance criteria is complicated, with remaining fundamental obstacles. This paper intends to give a general overview.


2018 ◽  
Vol 928 ◽  
pp. 263-268 ◽  
Author(s):  
Anuchit Uchaipichat

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.


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.


2021 ◽  
Vol 25 (Special) ◽  
pp. 2-78-2-82
Author(s):  
Haider K. Ahmed ◽  
◽  
Mohammed A. Abdulrehman ◽  

Two types of nanomaterial: Tio2 nanoparticles (NPs) and carbon black NPs have used in this research to study their effect on compressive strength, shrinkage and flow table tests Cement mortar. The mixing ratio was 1:2.7:0.485 (cement, sand, water/cement ratio) for compressive strength test and 1:2 (cement, sand) with the water/cement ratio was a variable value for dry shrinkage test. The two nanoparticles’ ratios are (0.25%, 0.75%, 1.25 % and 1.75%) by weight of the Portland cement. The test results show that the highest value of compressive strength was obtained when using Tio2 at 1.25% wt. of cement. But when using carbon black nanoparticles, the greatest value was obtained when adding it with a ratio of 1.75 % wt. of cement. Using two NPs when added to cement mortar has a negative effect on the shrinkage value.


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