Development of strength models for prediction of unconfined compressive strength of cement/byproduct material improved soils

© 2017 ASTM International. All rights reserved. This paper presents the possible inclusion of pulverized fuel ash (PFA) and ground granulated blast slag (GGBS) in cement deep soil mixing for enhancement of unconfined compressive strength (UCS) of weak soil materials for construction purposes. The main focus of this paper was to investigate the UCS of cement-, cement/PFA-and cement/PFA/GGBS-improved soils, and development of mathematical and graphical models for prediction of UCS for use in design and construction. Samples of cement, blends of cement and PFA, and cement/PFA/GGBS were prepared using 5 %, 10 %, 15 %, and 20 % by weight of dry soil and tested for UCS after 7, 14, 28, and 56 days. A multiple regression analysis was conducted using the SPSS computer program. The results showed that soil materials with lower plasticity show higher strength development compared to those of higher plasticity for cement improvement. The study has also revealed that the inclusion of PFA and GGBS can cause a reduction in the amount of cement in deep soil mixing, which can result to reduced cost and emission of carbon dioxide (CO2) during construction. The developed mathematical and graphical models could give reliable predictions of UCS for weak soil materials with initial UCS less than or equal to 25 kPa and for water to binder ratio of unity based on the observed agreement between experimental and predicted data. The developed multiple regression models have also been validated using different mixtures of 6 %, 8 %, 12 %, and 16 % of binders

Evaluation Of Laboratory Performance Of Sasobit And Zycotherm As An Additives For Warm Mix Asphalt On Performance Characteristic

Warm Mix Asphalt (WMA) is a fast emerging green technology which has a potential to replace Hot Mix Asphalt (HMA) and significantly reduces the production temperature of asphalt mixtures through lowering the viscosity of asphalt binders. The technology can reduce production temperatures by as much as 30 percent. Asphalt mixes are generally produced at 150º C or greater temperatures depending mainly on the type of binder used. WMA mixes can be produced at temperatures of about 135ºC or lower.This paper presents the findings of an experimental study aimed at evaluation of Marshall mix design and moisture-induced damage properties of Sasobit and Zycotherm modified WMA mixtures and were compared with HMA mixtures. Marshall mix design and moisture-induced damage properties were evaluated for varying dosage rate of WMA additives (1% to 5% of Sasobit by weight of binder with increment of 1% and 0.05% to 0.2% of Zycotherm by weight of binder with increment of 0.05%). Marshall mix design properties which include bulk specific gravity of compacted mixes (Gmb), air voids (VTM) content, voids filled with mineral aggregates (VMA) and voids filled with asphalt (VFA) were evaluated. Moisture-induced damage was evaluated by the Tensile Strength Ratio (TSR) approach and boiling water test. Test results indicate that WMA mixtures satisfied requirements of mix design properties. Further, WMA mixtures exhibited higher resistance to moisture-induced damage and fulfilled the minimum TSR requirements. In addition, dosage rate of WMA additives had significant effect on both Marshall mix design and moisture-induced damage properties

Influence Of Steel Fiber Reinforced Characteristics On Mechanical Strength And Abrasion Resistance Of Cement Concrete Pavement

Fibers are generally used as resistance of cracking and strengthening of concrete. Steel fiber is one of the most commonly used fibers. Short, discrete steel fibers provide discontinuous three-dimensional reinforcement that picks up load and transfer stresses at micro-crack level. Plain, unreinforced concrete is a brittle material, with possesses a very low tensile strength, limited ductility and little resistance to cracking. In order to improve the strength of concrete various types of fiber reinforced concrete are being used against plain concrete due to their higher flexural strength, better tensile strength, modulus of rupture and crack resistance.  The present study is to evaluate the performance of steel fiber reinforced concrete pavement with regard to compressive strength, split tensile, flexural strength, cantabro abrasion loss by varying the percentage of steel fibers from 0.5%, 1%,1.5%,2%,2.5%,3%  by weight of concrete were found out . The type of steel fiber used is of hooked end with aspect ratio 60. The obtained result shows that increase in percentage of steel fiber up to 2% gives the optimum the strength for compressive strength,flexural strength and cantabro abrasion test. And for split tensile strength 1.5% addition of steel fiber gives the maximum strength of cement concrete pavement than the plain concrete

Evaluation Of Structural Performance Of Pervious Concrete Containing Waste Tire Rubbers

Pervious concrete provides a sound solution for managing storm waters in built environments where the water runoff as well as the natural recharge of the groundwater is an important issue. The use of pervious concrete is also commonly related to other environmental benefits such as the urban heat Island reduction, traffic noise absorption, and pollutant filtering. At present the disposal of waste tires is becoming a major waste management problem in the world. Hence efforts have been taken to identify the potential application of waste tires in civil engineering projects.  In this context, our present study aims is to investigate the optimal use of waste tire rubber as fine aggregate in pervious concrete composite.  The properties of rubberized plain pervious concrete in terms of the mechanical properties and the permeability were investigated. Two types of rubber (crumb rubber and tire chips) were used in the production of rubberized plain pervious concrete mixtures which obtained by partially replacing the fine aggregate varying from 5% to 20% were considered as experimental parameters. The results are compared with non-rubberized pervious concrete (control) mixture. Rubber incorporated pervious concretes had lower compressive strength, splitting tensile strength, and modulus of elasticity with the increased percentage of replacement. Pervious concretes produced in this study fulfil this requirement as the minimum compressive strength being 4.2 MPa in the mix 20TC (tire chips). Permeability coefficients (K) of the rubberized pervious concretes fell between 0.025 and 0.61 cm/s which are recommended limits for pervious concretes

Sustainable Studies On Structural Performance And Thermal Cycle On Cement Concrete Pavement With Using GGBS

Due to the increase in construction industry which results the demand of concrete rapidly, Therefore the Production of cement involves emission of large amounts of carbon-dioxide gas into the atmosphere, a major contributor for green house effect and the global warming, The utilization of supplementary cementation materials is well accepted, since it leads to several possible improvements in the concrete composites, as well as the overall economy. The aim of our investigation is to determine GGBS as partial replacement of cement with compare to conventional cement concrete pavement. In the present study M20 grade of concrete were consider, With the W/C ratio as 0.5 were used.  The specimens are casted for investigating the mechanical properties like Compression strength, Flexural, and Split tensile, Thermal cycle compressive strength tests. The percentage of Cement is replacing by 5%, 10%, 15%, 20%, 25% and 30% of GGBS. The results were founds to be satisfactory with percentage replacement of 15 to 30%

Experimental Investigation On The Properties Of Cement Concrete Pavement Using Waste Plastic

In this study sand is replaced by waste plastic in two methods, one is by direct replacement in which shredded waste plastic is added directly to concrete and another is by melting plastic with fine aggregates. Density of conventional concrete is high; hence use of plastic in concrete reduces its self-weight. As plastic is not a biodegradable material, it affects the ecological system very badly. Waste plastic is not able to manage, so people started using waste plastic in bituminous pavement construction by replacing bitumen by waste plastic or by addition of waste plastic. There are different types of plastic is available depending on chemical composition and density. Plastic can also be used in form of fibers. In this study concrete with 5% and 10% replacement of plastic with sand which is direct replaced and replacement by melting process. For this study different physical and mechanical properties of concrete were conducted

Experimental Investigation On The Properties Of Pavement Using Waste Plastic In Road Construction

Due to the tremendous increases in population and changes in life style Waste plastic material Management playsan important role and one of the most powerfulconcepts in recent year.Therefore the disposal of waste plastic is a hazardous and become a serious problem globally due to their non-biodegradabilityand burning of these waste plastic bags causes highly environmental pollution.A study was conducted on use of waste Polyethylene Terephthalate in bitumen mixes. Marshall Stability and flow values were used to determine strength and deformation characteristics Strength. A comparison was made between conventional bitumen mixes and Marshall Values of modified mixes. Ideal percentage of waste PET polymer in bitumen mixes was found by varying the % of PET. An investigation was carried out on bituminous mixes modified by addition PET by fix mixing temperature.The PET was added in2 – 12 % (by the weight of optimum bitumen).We can conclude that the stability of PET modified bituminous binders is better compared to that of conventional bituminous binders. Use of waste plastic in bituminous binders contribute protection of environmen

Study on the Performance Characteristics and its Practices of Total Quality Management

The investigation have produced different mixed results, made by various research designs used in different area which used as apparatus to measure TQM and their performance. A collective study was made to recognize the performance study on the impact and non impact of this performance on various stages. Planning study design with the proposed explanation which is evaluated from various employees from different representatives and their data were collected which were gather from the different sources. Structural model with the support of the proposed model gathered from different Sources with the support of the proposed hypotheses. The implications from the study from various researchers and practitioners are discussed and further research directions are offered