Percentage Of Cement Research Articles

Influence of cement particles on the mechanical and buckling behavior of laminated GFRP composites with variation of end conditions of buckling

Mechanical behavior of particle-loaded laminated composites depend upon the type of matrix, filler, reinforced fibers and architecture of fibers. Further, buckling behavior of a laminated composite varies with its end conditions, i.e. free-free or fixed-fixed. Failure mechanisms like delamination, debonding and fiber fracture vary with the end conditions of buckling. Presence of hard filler may also change the buckling behavior. Thus, in the present article, the mechanical and buckling behavior of cement loaded woven glass fiber reinforced epoxy matrix composites were investigated. Cement was varied as 1%, 3% and 5% by weight of epoxy. Thickness of composites were also varied as 3.1 mm, 4.4 mm and 6.3 mm by varying the number of reinforced glass fiber mats. Tensile, Izod impact and Vickers micro-hardness tests and, buckling tests under free-free and fixed-fixed conditions were performed to assess the mechanical and buckling behavior respectively. Fractured composites were analyzed under scanning electron microscope (SEM). The results showed that tensile strength decreased and hardness increased with increase in percentage of cement. Composites with minimum thickness showed lowest tensile strength. Critical buckling load increased with increase in thickness of composites for both end conditions. However, the nature of variation of buckling load with the percentage of filler varies for every thickness. SEM images showed that damage of composites mainly involved fiber breakage and delamination. Cement particles were effective in deflecting the advancing crack.

Effect of Lime and Cement on the Geotechnical Properties of an Expansive Soil

The phenomenon of clays swelling is the cause of possible disorders dependent on the movement of the soil. The technique of the stabilization to improve such a soil state using cement and lime is utilized all around the world. The stabilization of the soil can be a very important solution because it brings important modifications to their geotechnical properties. This document aims to study the influence of the lime and the cement on the geotechnical properties of the expansive soil. The studied mechanical properties are the plasticity, the compaction, the unconfined compression strength, the free swell and the shear strength characteristics of the soil with varying proportions of lime and cement, Properties of the untreated soil were determined. The percentages of lime and cement added are respectively 2 %, 4 %, 6 % and 8 % by the dry weight of the soil. The untreated soil values were used as points of comparison. The obtained results show a significant reduction in the plasticity index and in the percentage of free swell of expansive soil with the increase of the quantity of lime and cement. Also it has been found that the addition of lime and cement increases the optimum moisture content, the unconfined compression strength, and the shear strength of the soil. The soil used in this research was taken in the zone of Me’daourouch, near the city of Souk Ahras. This research work studied in particular three aspects, Such as the effect of admixtures cement and lime, the effect of the variation of the percentage of admixtures and the effect of curing time after mixing of admixtures on the stabilization.

Tobacco waste ash: a promising supplementary cementitious material

According to the European Cement Association, CEMBUREAU, in 2015, the global cement production was 4.6 billion tons. Traditional cement production emits approximately 1 ton of CO2 per ton of cement, which represents almost 80% of the total CO2 emissions of concrete and approximately 6% of the world’s emissions. Among supplementary cementitious materials, the use of agro-waste ash emerges due to its reduced CO2 emissions, chloride diffusion, and materials cost, in addition to its greater compressive strength. In Colombia, the disposal of agro-wastes, such as tobacco waste, is an environmental and economic concern. In this study, ash obtained from tobacco waste (TWA) was studied as a sustainable partial replacement for cement in hydraulic concrete. The TWA was reduced to a particle size of less than 75 μm and was characterized by X-ray florescence. A central composite design was used to study the influence of the ash replacement percentage of cement and the water/binder (w/b) ratio on the compressive strength at 28 days. The results show that it is possible to replace 10% of the cement with TWA using a 0.5 w/b ratio and obtain a 51% higher compressive strength than the control mixture at 28 days. Moreover, the experimental results demonstrated an improvement of 86% in the 7-day compressive strength when TWA was used.

The effect of replaced recycled glass on thermal conductivity and compression properties of cement

This study deal with recycling of waste colorless glass bottles which are prepared as a powder and use them as an alternative for cement to save the environment from west and reduce some of cement(ceramic) damage and interactions with conserving physical properties of block concrete. Different weight percentage (0%, 2%, 4%, 5%, 6%, 8%, 10%, 15%, 20% and 25%) of recycled glass bottle were use in this research to be replaced by a certain percentages of cement. Thermal conductivity was studied for prepared samples. Results show that the thermal conductivity decrease with the increase of weight percentage of glass powder comparing with the stander sample.

Effect of Lime and Cement on Unconfined Compressive and Shear Strength of Soil in Baleli and its Vicinity

This study was carried out with an intention to observe any sign of improvement of clayey silty soil due to addition of lime and cement. This paper focuses on the primary research of using blends of lime and cement on the soil of Baleli and its vicinity region to evaluate the features of cement and lime at the shear strength of unsaturated soil through carrying out direct shear and unconfined compression tests on soil samples. Soil admixed along with natural or artificial admixtures is one of the techniques to improve its physical characteristics, consequently we need to alter some features of soil that could make it expedient to calculate the bearing ability of the soil and even stabilize the weight bearing potential. The values obtained here are in comparison with unblended soil samples, at 5% admixed soil with cement and lime showed maximum angle of friction and moderate cohesion but shear strength 30.32 psi achieved at this percentage of lime and cement was greater than other percentages. The unconfined strength of this blended soil presented a compression of 86.32 N/mm2 at 0.0503 mm/mm percent strain which is lower than maximum percentages of lime and cement and conclusions are drawn toward the usability of lime and cement as a value effective approach. Soil sample admixed with 7% lime and cement presented less cohesion than those blended with 3% and 5% lime and cement but greater shear strength as compared to all of the samples including simple soil. The unconfined strength of this blended soil presented a compression of 115.32 N/mm2 at 0.0755 mm/mm percent strain which is lower than maximum percentages of lime and cement. As a significance, its miles better to combine distinctive types of soils collectively to improve the soil vitality back ground.

Effect of Lime and Cement on Unconfined Compressive and Shear Strength of Soil in Baleli and its Vicinity

This study was carried out with an intention to observe any sign of improvement of clayey silty soil due to addition of lime and cement. This paper focuses on the primary research of using blends of lime and cement on the soil of Baleli and its vicinity region to evaluate the features of cement and lime at the shear strength of unsaturated soil through carrying out direct shear and unconfined compression tests on soil samples. Soil admixed along with natural or artificial admixtures is one of the techniques to improve its physical characteristics, consequently we need to alter some features of soil that could make it expedient to calculate the bearing ability of the soil and even stabilize the weight bearing potential. The values obtained here are in comparison with unblended soil samples, at 5% admixed soil with cement and lime showed maximum angle of friction and moderate cohesion but shear strength 30.32 psi achieved at this percentage of lime and cement was greater than other percentages. The unconfined strength of this blended soil presented a compression of 86.32 N/mm2 at 0.0503 mm/mm percent strain which is lower than maximum percentages of lime and cement and conclusions are drawn toward the usability of lime and cement as a value effective approach. Soil sample admixed with 7% lime and cement presented less cohesion than those blended with 3% and 5% lime and cement but greater shear strength as compared to all of the samples including simple soil. The unconfined strength of this blended soil presented a compression of 115.32 N/mm2 at 0.0755 mm/mm percent strain which is lower than maximum percentages of lime and cement. As a significance, its miles better to combine distinctive types of soils collectively to improve the soil vitality back ground.

A Study on Mechanical Properties of Conventional Concrete and Coconut Shell Concrete by Replacing Cement with Silica Fume

High standing estimation of building materials utilized for development is a component of incredible concern. Coconut shell as a completely substitution in the place of coarse aggregate may totally effective for designers in construction industry. The coconut shell concrete is a light weight solid which may decrease the self-heap of a structure. The under taken project depends on inspecting attributes of coconut shell concrete when contrasted with conventional concrete. Coconut shells going from 10mm strainer and held on 6.3mm were considered to utilize for this study. For the current study M100 grade concrete is used to cast the specimens. The principle properties considered testing on coconut shell concrete and conventional concrete is compressive strength, split tensile strength and flexural strength. Examples were taken by supplanting coarse aggregate with coconut shells completely and cement is supplanted by silica fume with various extents of 5%, 10%, 15%, 20%, 25% for compressive strength test and tests were done at 3, 7, 28, 56 and 90 days of curing, it is observed that the ideal compressive strength outcomes were obtained at 10% of silica fume. The flexural strength and split tensile strength of the specimens are calculated with replacement of cement by silica fume with different extents of 0%, 5%, 10% and 15%, tests were done at 3, 7 and 28 days of curing. The optimum replacement percentage of cement by silica fume is 10% for compressive strength, split tensile and flexural strength. The primary principle is to lessen the utilization of natural aggregate by supplanting them with coconut shells and to decrease the density of concrete which makes concrete for simple dealing.

Stabilization of black cotton soil by using cement, lime and rice husk in flexible pavements

Expansive soil (Black cotton soil) is very weak and does not have enough stability for any type of construction work. To make the subgrade soil stable, by improving its engineering properties is very essential. In the present work, stabilization of subgrade soil by using Sand and Cement varying percentage of cement as 2%, 3%, 5% and constant percentage of sand by weight of soil, Rice Husk of 5%, 7%, 10%, and Lime is used to enhance the strength of subgrade soil. The purpose of this study is to determine the optimum dose of the stabilizer, which improves the strength and bearing capacity of soil less which is suitable for pavement structure. To evaluate the strength of soil, various tests have been performed such as Sieve analysis, Liquid limit, Plastic limit, Specific gravity, Compaction (OMC, MDD) and CBR test in the laboratory. The result shows that the use of the above materials in combination increases the California Bearing Ratio values (CBR). By using the CBR value the design of pavements to carry traffic in the range of 1 to 10 msa and 10 – 150 msa is calculated as per IRC: 37 – 2001.

Durability and Strength of Sustainable Self-Consolidating Concrete Containing Fly Ash

In this paper, the durability and strength of self-consolidating concrete (SCC) is assessed through development and testing of six binary mixes at fixed water-to-binder (w/b) ratio of 0.36. In each of the six SCC mixes, a different percentage of cement is replaced with fly ash. The development of compressive strength for each of the mixes is assessed by testing samples after 3, 7, and 28 days of curing. Durability of each of the six SCC mixes is assessed by measuring the charge passed in Rapid Chloride Permeability (RCP) test. Charge passed was measured in samples cured for 1, 3, 7, 14, 28, and 40 days of curing. All mixes out-performed the control mix in terms of resistance to chloride penetration. Binary mix in which 20% of cement is replaced with fly ash exhibited 28-day strength slightly surpassing the control mix.

Utilization of granulated blast furnace slag and cement in the manufacture of compressed stabilized earth blocks

This study involves the investigation on utilization of granulated blast furnace slag (GBFS) and cement in the manufacture of compressed stabilized earth blocks (CSEB). Two locally available soils from Dakshina Kannada district, Karnataka, India were tested for their index and strength properties with replacement of granulated blast furnace slag (GBFS). An optimum percentage of replacement of GBFS was established and then varying percentages of cement was added for the production of compressed stabilized earth blocks (CSEBs). This stabilized soil was used for the manufacture of blocks of size 305 mm × 143 mm × 105 mm. All the blocks were cast to a target density, followed by the curing for 28 days. The blocks were subjected to compression test and water absorption test according to Indian Standard (IS) specifications. The test results showed that the CSEBs prepared with GBFS and cement can be utilized in masonry for load bearing wall construction. A small percentage of cement is sufficient for manufacturing the CSEBs when optimum GBFS content is replaced with that of soil, thereby reducing the energy consumption.

Comparison between cement and fly ash geopolymer for stabilized marginal lateritic soil as road material

ABSTRACTThe stabilisation of marginal lateritic soil using cement and fly ash (FA) geopolymer with a liquid alkaline activator was investigated. In this study, soil with satisfactory gradation and percentage of wear was selected. Only the soaked California Bearing Ratio (CBR) value must be enhanced to satisfy the requirement to form a suitable pavement subbase material. Field CBR tests were conducted for both geopolymer- and cement-stabilised soils used as pavement subbase materials. The soaked CBR of cement- and FA-geopolymer-stabilised marginal lateritic soil of various mixing percentages at 14 days satisfied the standard requirements specified by the government agencies in Thailand. Equations were established from field test data to predict the CBR at any testing time. The CBR development of cement-stabilised soil took more time than that of geopolymer-stabilised soil. The appropriate mixing percentages of cement and FA geopolymer with marginal lateritic soil were 3–5 and 4–8%, respectively. Microstructural analysis indicated that the stabilised soil exhibited a denser structure, which corresponded to the CBR increment. The findings of this study will enable the implementation of cement and FA geopolymer as successful stabilisers for pavement subbase materials.

Determination of Optimum Cement Content for Stabilization of Soft Soil and Durability Analysis of Soil Stabilized with Cement

This research was aimed at finding the optimum cement content for achieving maximum compressive strength and stabilization in soft soil found in the periphery of the city of Chittagong. But, gaining strength was not considered enough unless it can be proved that strength was gained without compromising the durability. As such, durability test was performed on the samples stabilized with different percentages of cement. In this research three different soil samples were used. The samples were collected from three different areas within the city where future expansion of the city is expected. Six different percentages of cement by weight of soil: 0%, 2%, 4%, 6%, 8%, and 10% were used. Cement was mixed with soil at optimum moisture content. Cubes were casted and their compressive strengths assessed after a curing period of 7, 14 & 28 days. The durability test was done in two different cycles: 2 days wetting-drying and 7 days wetting-drying within a time frame of 28 days. The volume and weight were monitored after completion of each cycle of wetting and drying. The performance of the soils modified with different percentages of cement were assessed using Standard Proctor Test, Unconfined Compression Test and Durability Test. It was found that compressive strengths in the samples under test increased with the increase of cement content up to 8%. But when cement content is increased above 8%, the compressive strength increased but in a slower rate. At the end of durability test, it was observed that volume, and weight of the soil samples produced with 2, 4 and 6% cement changes with the variation in wetting and drying periods. But when the cement percentage is increased by 6%, preferably increased to 8%, no appreciable change in weight and volume were observed after the wetting and drying cycles. The samples going through the two days wetting and drying cycles under durability test showed greater unconfined compressive strength compared to samples going through seven days durability cycle of wetting and drying. It may be mentioned here that the three soil samples stabilized with cement did not show any major degradation in compressive strength during durability test.

Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer

The purpose of this research was to investigate the effects of recycled asphalt pavement (RAP) and cement content on the permeability and bearing capacity characteristics of aggregate base courses. Mixtures containing untreated RAP ranging between 0 and 100 percent and 1, 2, and 3% cement-treated RAP were subjected to laboratory tests (bitumen content, sieve analysis, modified proctor, soaked California bearing ratio (CBR), and constant-level permeability tests). The results showed that, as the RAP percentage in the mixture increased, CBR values decreased considerably. Moreover, there is a linear increase in the CBR values with cement treatment. Optimum moisture contents (OMC) and maximum dry densities (MDD) showed a decreasing trend. Increasing the cement percentages in 100% RAP blend increases the OMC and MDD values. The permeability of RAP showed a decrease as the percentage of RAP and cement increased in blends. The study showed that the CBR value of the 20% RAP blend is also obtained in the 100% RAP/3% cement-treated blend. Thus, it has been understood that cement is a suitable material in order to increase the use of RAP. In addition, the increase in the percentage of RAP and cement made the base course more impermeable.

The effect of using synthetic fibers on some properties of modified juss

This paper examines the mechanical properties of a composite material made of modified Iraqi gypsum (juss) reinforced with polypropylene fibers. The modified juss was prepared by adding two percentages of cement (5, 10) %. Two percentages of polypropylene fibers were used, to reinforce the modified juss (1, 2) %. The water/dry compound ratio used was equal to 0.53%. The composite was evaluated based on compressive strength, flexural strengths, absorption percentage, density, acoustic impedance, ultra - pulse velocity, longitudinal shrinkage and setting time tests. The results indicated that the inclusion of cement on to juss increases the compressive strength, absorption percentage, density, acoustic impedance, ultra - pulse velocity, longitudinal shrinkage and a reduction in flexural strength and setting time were observed by adding the cement. In addition, the inclusion of polypropylene fiber was significant in improving mechanical performance of the composite material, it shows a great improvement in longitudinal shrinkage, modulus of rupture and absorption percentages.

Effect of soil stabilized by cement on dynamic response of machine foundations

Machine foundations require significant attention from designers. The main goal of the design of machine foundation is to limit the amplitude displacement and not disturb the people who work near the machine. In some cases, if the design of machine foundations does not satisfy the acceptable value of the dynamic response (such as maximum amplitude of displacement), the stabilization of soil under the machine foundation may be used to decrease the amplitude of displacement. This paper outlines effect of stabilized soil under the foundation by cement on the displacement response of machine foundations. Three-dimensional analyses by using finite element method are carried out to investigate the effect of depth of stabilized layer with different percentage of cement content on the dynamic response of the machine foundation. In addition, the effect of area stabilized by cement material on the dynamic response of machine foundation is investigated. The results shown that, the dynamic response of machine foundations generally decreases with increasing the depth of soil layer stabilized with cement. A significant decrease in the displacement of machine foundations is occurred for the stabilized soil layer with a depth of two times of the width of foundation, and the optimum percentage of cement for stabilizing is 6%.

Effect of Margin Level Setting in Abutments Created by CAD/CAM on Residual Cement

Background: Various complications of dental implants have been reported as cases with long-term implant use increase with its spread of use. It has been reported that residual cement is involved in approximately 80% of the peri-implantitis cases, and prompt management of residual cement is important. This study examined cementation of the superstructure and how the level of gingival margin of abutments affected the amount of residual cement. The study also examined the level of abutment margin to avoid residual cement.Materials and Methods: Working models were prepared using epoxy resin. Implants were placed in one part of the maxillas. Silicone rubber was used to simulate peri-implant gingiva. Morphological designing was performed for the abutments and superstructures on the prepared models. The examination was performed on four levels of abutment margins: the same level as the margin of the gingiva (ML0), 1 mm subgingival (ML-1), 2 mm subgingival (ML-2), and 3 mm subgingival (ML-3). Temporary cement was placed in each superstructure which was then placed on the abutment. An access hole was created on the superstructure, and the abutment and superstructure were removed from the model. Observations were made on the cement remaining subgingivally (residual cement). The cement above the margin and residual cement were collected.Results: If the margin level was subgingival, there was a tendency for residual cement to adhere to the entire subgingival area regardless of the margin depth. The residual cement weight percentage was significantly higher for the ML-2 and ML-3 margins than for ML-0 margins. The percentages of supragingival cement did not differ significantly among different abutment margins.Discussion and Conclusion: The results of this study suggest that when the abutment margin is ML-2 or lower, the cement does not extrude supragingivally and tends to remain subgingivally.

Performance and Microstructural Analysis of Lightweight Concrete Blended with Nanosilica under Sulfate Attack

The influence of two lightweight aggregates (LWA) on concrete and the effects of cement substitution for nanosilica (NS) on the interfacial transition zone (ITZ) and cementitious matrix of concrete in resistance to attacks by magnesium sulfate (MgSO4) are researched in this work. The aggregates evaluated were perlite, which is a lightweight aggregate of open porous structure, and expanded clay (aliven) with closed porous structure. The variables included in the study were replacement percentage of coarse aggregates by lightweight coarse aggregates (0 and 100% by volume) and replacement percentage of cement by nanosilica (0 and 10% by weight). In the dosage of the mixtures, water/cementitious‐material ratio constant of 0.35 was used. The LWA were characterized by XRD, XRF, and SEM techniques. Compressive strength, water absorption, and volume change in magnesium sulfate solution (according to ASTM C1012 for a period of 15 weeks) of lightweight concretes were evaluated. It was found that the nanosilica had effect on refinement in the pore system; however, the main incidence on the compressive strength and durability of lightweight concrete (LWC) was defined by the characteristics of lightweight aggregate used in its preparation.

Influence of cement content on the thermal properties of compressed earth blocks (CEB) in the dry state

The Compressed Earth Block (CEBs) is one of the kinds of building materials which stabilized by cement. Soil is a basic component, a renewable, non-toxic and natural resource. Samples must be stabilized with a limited percentage of cement so that samples do not lose their natural properties including thermal comfort and on other hand offer high mechanical resistance. The objective of this work is to study the effect of cement content on thermal behavior of the building material of CEBs in the dry state, by studying variation of temperature with time, and measuring thermal conductivity and the specific heat, with respect to the various cement ratios added to the samples. This study is mainly an experimental and numerical, to determine how the thermal behavior evolves with the cement content in the samples CEBs. The soil was extracted from the famous city Fez in Morocco, Fez is known for its several historical monuments and buildings. After determining its granulometry and other specific characteristics, the CEBs are made by mixing soil with cement. The samples are put in plastic bags for two weeks, then removed the plastic bags from the samples and let them to dry again for an additional two weeks away from direct sun. The samples CEBs are taken cylindrical form (8 cm diameter with an average height of 12 cm).The experimental method consists of a hot ring for which a numerical modelization was developed to fit the mathematical equations of heat diffusion and the boundary conditions. For the numerical model Bouabid and Cherraj have developed numerical model which allow, with a good accuracy, to quantify the evolution of the thermal behavior of the earth material in function of cement content.Indeed, the study provides information on the influence of the cement percentage on the thermal behavior of the samples CEBs, the thermal behavior of samples increase with increase cement content.

Treatment of Radiological Medical Waste Using Concrete Cubic Molds

Concrete cubic molds were made and manufactured using a fixed percentage of cement and sand to be as a container for the radiological medical waste in order to prevent radiation during the transfer of radioactive waste from hospitals to their own landfill sites to preserve the safety of people and the environment from radiation pollution. The maximum dose rate was 173.744 µSv/h in NHTc2 sample measured using RAD EYE B20 dosimeter, which has a very high activity as a medical waste (28.568 µCi), while the lowest dose value 0.297 µSv/h and activity 0.041 µCi was for MCI4 sample, except the dead samples which less than detection limit for the NaI(Tl) system. Also, the efficiency calculations of manufactured molds with thickness 3 cm were done by using Ba-133 and Cs-137 as a point source, because of the energies of these sources are close to that for I-131 and Tc-99 m exist in the medical waste samples. The shielding percentages were calculated and have very high values with using concrete molds, and the dose rate decreases with increasing the sand in the mold. Measurement of resistivity to compression for the molds were done to acknowledgment the strength to hold radiological waste through transfers or store of these kinds of waste. We found that the increase of the cement percentage (chosen 10, 20 and 30%) leads to increasing the mold strength.

STABILISASI TANAH TAMBAK DENGAN VARIASI CAMPURAN SEMEN ANDALAS SEBAGAI LAPISAN SUBGRADE

This paper discusses the results of the study, conducted to determine the effect of variations in cement content of the waiting time of curing (curing time) after the mixing process with a ground. Soils studied were from Jalan Simpang Loskala Pertamina Lhokseumawe. Portland cement used is the type of Andalas, with mixtures of two kinds of variation is 3% and 5%, a waiting period of 1 day, 3 day and 7 days. Physical properties of the test results, according to AASHTO; land into group A, 2-6, while according to the USCS; the land is included in group SC (sandy clay), visual observation as well, so the soil is sandy silt soil type, so it is non-cohesive and did not have a value of plasticity. Based on laboratory testing showed that the addition of the percentage of cement can increase the bearing capacity of the soil as well as the duration of curing.Keywords: cement content, bearing capacity, duration of curing