375 research outputs found
Laboratory Investigation of Dry Lean Concrete with Copper Slag
No full textAt present about 33 million tonnes of copper slag is generated annually worldwide, India
contributing 6 to 6.5 million tones of this slag. As per scientific estimate, for every tonne of
copper metal produced, around 1.8-2.2 tonnes of slag is generated. In states like Kerala,
Maharashtra and Gujarat, sand mining in rivers has already been banned owing to its
disastrous impact ecology. “Therefore, slag has a big potential of getting developed as a
suitable alternative material to these resources”. With increasing shortage of river sand and
natural aggregates across the country, construction sector is under tremendous pressure to
explore alternative to these basic construction material to meeting growing demand of
infrastructure demands.
The reuse of waste materials derived from industry waste is growing all over the world. One
of the most environmentally responsible ways of meeting the challenges of sustainability in
construction is the use of slag in new construction. The main objective of the study is to
investigate the effect of using copper slag in lieu of natural fine aggregate on strength
properties of Dry lean Concrete.
Dry Lean Concrete (DLC) is an important part of modern rigid pavement. It is a plain
concrete with a large ratio of aggregate to cement than conventional concrete and generally
used as a base/sub-base of rigid pavement. The compaction of DLC is done under 10 to 12T
vibratory roller in field , that’s why it is also known as Roller – Compacted Concrete or RCC
concrete.
From all the combination it is observed that Density is maximum(2.571 g/cc) of the mix (SCS-
20-80) where 20% Fine Aggregate and 80% Copper Slag at 5.0% moisture content from
this we can say that density of mix increases with the increases of copper slag in the mix and
it uses less moisture content. It is due to the density of copper slag is more that the densities
of sand and copper slag also having a less water absorption.
From all the combinations of mixes it observed that Compressive Strength of 28days is
maximum(22.49 N/mm2) of the mix S-CS-60-40 at 5.0% moisture content
From all combination it is concluded that although 28days compressive strength is Maximum
in the Mix S-CS-60-40 but compressive strength (28 days) of Mixes S-CS-40-60 & S-CS-20-
80 are also very near to the maximum strength 22.35 N/mm2 and 21.98 N/mm2 respectively
at the same moisture content
Anomalous structure and dynamics of the Gaussian-core fluid
No full textIt is known that there are thermodynamic states for which the Gaussian-core fluid displays anomalous properties such as expansion upon isobaric cooling (density anomaly) and increased single-particle mobility upon isothermal compression (self-diffusivity anomaly). Here, we investigate how temperature and density affect its short-range translational structural order, as characterized by the two-body excess entropy. We find that there is a wide range of conditions for which the short-range translational order of the Gaussian-core fluid decreases upon isothermal compression (structural order anomaly). As we show, the origin of the structural anomaly is qualitatively similar to that of other anomalous fluids (e.g., water or colloids with short-range attractions) and is connected to how compression affects static correlations at different length scales. Interestingly, we find that the self-diffusivity of the Gaussian-core fluid obeys a scaling relationship with the two-body excess entropy that is very similar to the one observed for a variety of simple liquids. One consequence of this relationship is that the state points for which structural, self-diffusivity, and density anomalies of the Gaussian-core fluid occur appear as cascading regions on the temperature-density plane; a phenomenon observed earlier for models of waterlike fluids. There are, however, key differences between the anomalies of Gaussian-core and waterlike fluids, and we discuss how those can be qualitatively understood by considering the respective interparticle potentials of these models. Finally, we note that the self-diffusivity of the Gaussian-core fluid obeys different scaling laws depending on whether the two-body or total excess entropy is considered. This finding, which deserves more comprehensive future study, appears to underscore the significance of higher-body correlations for the behavior of fluids with bounded interactions.Intramural NIH HHSChemical Engineerin
Laboratory investigations of dense bituminous macadam (grade 1) mix using different types of additives
No full textM. E. Civil (Infrastructure Engineering) ThesisIndia has a road network of over 4,236,000 kilometres, the third largest in the world. The road transport carries close to 85% of passenger traffic and 70% of freight transport. The properties of bitumen and bituminous mixes can be improved to meet requirements of any pavement with the incorporation of certain additives or a blend of additives. Bituminous mixes can be prepared and used in a pavement section for a bituminous binder course using different types of additives such as Polymers, Crumb Rubber and waste materials like discarded tube tyres, plastic bottles and rice husk ash. Modified bituminous mixes are expected to give higher life of surfacing depending upon degree of modification and type of additives used.
The consumption of plastics is increasing day by day. Nearly 50 to 60% of the total plastics are consumed for packing. Once used plastic materials are generally thrown out as they do not undergo bio-decomposition. Hence, they are either land filled or incinerated. Both are not eco-friendly processes as they pollute the land and the air. Similarly, waste tyres in India are categorized as solid hazardous waste. It is estimated that about 60% of waste tyres are disposed via unknown routes in the urban as well as rural areas. The hazards of waste tyres include- air pollution associated with open burning of tyres, aesthetic pollution caused by waste tyre stockpiles and illegal waste tyre collecting and other impacts such as alterations in hydrological regimes when gullies and watercourses become waste sites.
The present study aims at developing bituminous mixes for the Dense Bituminous Macadam (DBM) Grade 1 incorporating the plastic wastes, waste tyre tubes and rice husk ash as partial replacement of the bitumen content. Also the study focuses on the DBM Grade 1 mixes with different blends by using Crumb Rubber Modified Bitumen (CRMB) and Polymer Modified Bitumen (PMB). In this study, the Stability-Flow analysis for the various DBM Grade 1 mixtures with modified binders and with different percentage replacement of bitumen with plastic wastes, waste tyre tubes and rice husk ash are reported. It is found that of the three materials used, replacement of OBC by 10% discarded tyre tube has the highest stability value. The optimum content of CRMB and PMB for use in DBM Grade 1 mix is 5%. Also the bituminous mixes of DBM Grade 1 with 5% PMB having 40% stone dust shows the maximum stability value and the bituminous mixes of DBM Grade 1 with 5% CRMB having 44% stone dust shows the maximum stability value.Civil Engineering Department, Thapar University, Patial
Characterization of Epoxy Modified Asphalt
No full textAsphalt pavements serve as the foundation of our transportation system, and their
durability and effectiveness heavily rely on the properties of bitumen, which acts as the
adhesive agent binding the aggregate materials together. Modified asphalt binders offer
improved performance by enhancing the mechanical characteristics and resistance to
rutting and fatigue of asphalt pavements.
Epoxy resin is a type of synthetic thermosetting polymer that is widely used in various
industries and applications. It is created through a chemical reaction between epoxide
monomers and a curing agent, typically a hardener. The resulting material is a highly
durable and versatile substance with a wide range of properties.
This study aims to investigate the impact of epoxy modification on asphalt binder &
mixtures properties. The base bitumen (VG 30) was modified by incorporating epoxy
(combination of epoxy resin and hardener) at different contents of 1%, 2%, 3%, and 4%
by weight of heat binder. The rheological properties of the binders were evaluated
through tests such as high-performance grade (PG), MSCR (multiple stress creep and
recovery), frequency sweeps, temperature sweeps, amplitude sweeps, SFP (Superpave
fatigue parameter), LAS (linear amplitude sweep), and BBR (bending beam rheometer)
tests. The mixture properties were tested through Marshall stability, ITS (indirect tensile
strength), and TSR (tensile strength ratio) tests.
Through comprehensive analysis, the optimal dosage of the additive was determined to
be 2-3% by weight, resulting in the most favourable modified asphalt binder and mixture
properties. Pavement structural analysis showed that the selected pavement composition
had the ability to resist higher traffic based on rutting and fatigue criteria as per IRC: 37-
2018 when epoxy-modified bituminous concrete (BC) mixtures were used in the wearing
course, than the mixture with unmodified VG 30 binder
Effect of Fly Ash & Ground Granulated Blast Furnace Slag as Cement Replacement Materials on Strength and Durability Characteristics of Pavement Quality Concrete (PQC)
No full textME, CED, DissertationThe major problem the world is facing today is the environmental pollution. The best way to dispose any waste material is to use it as one or the other forms like construction material. The Ordinary Portland Cement (OPC) is one of the main ingredients used for the production of concrete. Unfortunately, production of cement causes emission of large amount of carbon-dioxide gas into the atmosphere, a major contributor for greenhouse effect and the global warming. Also, Portland cement being very expensive material affects the total cost of construction of any project. Hence, the researchers are currently focused on use of waste material having cementing properties, which can be added in cement concrete as partial replacement of cement, without affecting its strength and durability, which will result in decrease of cement production thus reduction in emission of greenhouse gases, global warming and the cost of construction.
The ground granulated blast furnace slag and fly ash are the waste products from the iron manufacturing and thermal plant industry respectively, which may be used as partial replacement of cement in concrete due to its inherent cementing properties.
The present study aims at, developing pavement quality concrete mixtures incorporating ground granulated blast furnace slag and fly ash as partial replacement of cement. In this study, the flexural, compressive and rapid chloride permeability test for pavement quality concrete mixtures for different percentage of GGBS and fly ash as replacement of cement are reported. It is found out the maximum increase in flexure strength is for 20% fly ash and 60% GGBS. The increase in compressive strength is maximum for 10% fly ash and 50% GGBS. From durability point of view, we can use all the mixes as their permeability is very low.CED, Thapar University, Patial
Effect Of Steel Fibres And Marble Dust On Strength Characterisitcs Of Pavement Quality Concrete
No full textM.E, CEDThere is growing interest in the construction of concrete pavements, due to its high strength, durability, better serviceability and overall economy in the long run.
The thrust nowadays is to produce thinner and green pavement sections of better quality, which can carry the heavy loads. The high strength steel fibre reinforced concrete is a concrete having compressive strength greater than 40MPa, made of hydraulic cements and containing fine and coarse aggregates; and discontinuous, unconnected, randomly distributed steel fibres.
The present study aims at, developing pavement quality concrete mixtures incorporating marble dust as partial replacement of cement as well as steel fibres. The aim is to the design of slab thickness of PQC pavement using the achieved flexural strength of the concrete mixtures. In this study, the flexural, compressive and split tensile strength for pavement quality concrete mixtures for different percentage of steel fibres and replacement of cement with marble dust are reported. It is found out the maximum increase in flexure strength, compressive strength and split tensile strength is for 0% Marble Dust and 1% Steel fibre. Also it has been possible to achieve savings in cement by replacing it with marble dust and adding fibres.
This study also shows that in view of the high flexural strength, high values of compressive strength and high values of split tensile strength, higher load carrying capacity and higher life expectancy, the combination of 10 to 20% marble dust replacement along with addition of 0.5 to 1% steel fibres is ideal for design of Pavement Quality Concrete (PQC).Thapar Universit
Comparison of Different Programs for Analysing Falling Weight Deflectometer Data
No full textME ThesisIndia has very large road network consisting of Expressways, National Highways,
State Highways, District Roads and Rural Roads. In recent time, suitable maintenance
and evaluation of road network is necessary requirement for any nation for its
economic development. Evaluation of large road network is very difficult task for
highway authorities. For the construction of expressways and highways huge amount
of money is invested in India. There is need to evaluate these facilities regularly in
terms of functional and structural performances to determine requirement for
maintenance and rehabilitation measures. For structural evaluation, currently FWD is
very popular because it simulates actual loading conditions of vehicles. As the use of
the FWD is increasing the number of methods adopted for back-calculation of
modulus values is also increasing. The use of these back-calculation methods without
proper analysis may provide unreliable results.
Therefore in order to decide the appropriate back-calculation methodology,
there is a need for evaluation of different programs. The purpose of this study is to
summarise the literature available on evaluation of different programs for analyzing
FWD data throughout the world. This study discusses the process followed by various
researchers for selecting various programs, back-calculation procedure used and
outcomes of the program evaluations. The focus of thesis work is mainly on analysis
of FWD data to compute moduli values of different layers obtained from different
programs. In this study five back-calculation methods; namely, KUAB, EVERCALC,
KGPBACK, Elmod (Deflection Basin Fit and Radius of curvature methods) are
evaluated for consistency and reliability. Some Analytical methods AASTHO (1993),
Garg and Thompson (1999), Roque (1998) were also used for determination of
subgrade modulus values. These back-calculated modulus values were compared with
laboratory calculated modulus values. Modulus values from different programs are
compared using Pearson correlations and Statistical analysis
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