Research Papers

By
Kaushal Kishore, Materials Engineer, Roorkee

ABSTRACT:
The stresses induced in concrete pavements are mainly flexural. Therefore flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. A simple method of concrete mix design based on flexural strength for normal weight concrete mixes is described in the paper.

INTRODUCTION:
Usual criterion for the strength of concrete in the building industry is the compressive strength, which is considered as a measure of quality concrete. However, in pavement constructions, such as highway and airport runway, the flexural strength of concrete is considered more important, as the stresses induced in concrete pavements are mainly flexural. Therefore, flexural strength is more often specified than compressive strength in the design of concrete mixes for pavement construction. It is not perfectly reliable to predict flexural strength from compressive strength. Further, various codes of the world specified that the paving concrete mixes should preferably be designed in the laboratory and controlled in the field on the basis of its flexural strength. Therefore, there is a need to design concrete mixes based on flexural strength.
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By
Kaushal Kishore
Materials Engineer, Roorkee

INTRODUCTION
The standard method of determining strength of hardened concrete consists of testing concrete cubes in compression. The quality of entire concrete of a structure cannot be fully assessed by testing a few concrete cubes. The results obtained in testing cubes do not always reflect the actual strength of concrete in construction. In a whole day, concreting work cubes are cast in a few batches, the differences (unintentional and intentional) in the composition are not uncommon, their compaction and their hardening conditions always differ more or less from those of the structure. In addition, the number of test cubes is generally so small that they can only be considered as random tests. Some times, in case of failure of cubes, doubtful concrete, cracks, deterioration of concrete, etc. it becomes necessary to assess the quality and strength of concrete of the structure. As far back as early thirties, the necessity was felt to develop instruments by which in-situ strength of concrete may be obtained. Various non-destructive methods of testing concrete have been developed, which include, Firing method, Skramtayev’s method, Polakov’s method, Magnitostroy method, Fizdel ball hammer, Einbeck pendulum hammer, Ball indentation hammer, Rebound hammer, Pull out techniques, Windsor probe, Ultrasonic pulse velocity methods, Radioactive and nuclear methods, Magnetic and electrical methods. In all these methods of tests, due to simplicity, rebound hammer test based on surface hardness becomes most popular in the world for non-destructive testing of in-situ concrete.

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By
V Kartik Ganesh
Department of Civil Engineering, SRM University
Kattankulathur, Chennai-603203, INDIA

Abstract
The innovation of relevant nanotechnology and its significance in civil engineering practice is illustrated in this paper for broadening vision. Nanotechnology deals with understanding, controlling and manipulating matter at the level of individual atoms and molecules in the range of 0.1–100 nm (10-9 m). It creates materials, devices, and systems with new properties and functions. The role of nanotechnology in the conceiving of innovative infrastructure systems has the potential to revolutionize the civil engineering practice and widen the vision of civil engineering. Following this the analysis were carried out in ductile structural composites along with its enhanced properties, low maintenance coatings, better properties of cementitious materials, reducing the thermal transfer rate of fire retardant and insulation, various nanosensors, smart materials, intelligent structure technology etc. The properties like self-sensing, self-rehabilitation, self-cleaning, self-vibration damping, self-structural health monitoring and self-healing are the key features. To execute these, the gap between the nanotechnology and construction materials research needs to be bridged. This paper first presents the background information and current developments in nanotechnology and civil engineering in general followed by the merits and demerits of their interdisciplinary approach. Further the details of application oriented nanotechnology-enabled materials and products that are either on the market or ready to be adopted in the construction industry and also their possible consequences over the time is elucidated. Some of the major instances of current applications of nanotechnology in the field of civil engineering across its different sections around the globe are exemplified. The most challenging economic factors concerned with its practicality are discussed briefly. Finally the future trend, potential and implications of nanotechnology development in civil engineering towards more economical infrastructure, low cost maintenance with longer durability are deliberated.

Keywords—Civil Engineering, Nanomaterials, Nanotechnology, Sustainability.
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By
Miss.P.R. Bhivgade

Abstract:– Bridge construction today has achieved a worldwide level of importance. Bridges are the key elements in any road network Use of box girder is gaining popularity in bridge engineering fraternity because of its better stability, serviceability, economy, aesthetic appearance and structural efficiency. The structural behavior of box girder is complicated, which is difficult to analyze in its actual conditions by conventional methods. In present study a two lane simply supported Box Girder Bridge made up of prestressed concrete which is analysis for moving loads as per Indian Road Congress (IRC:6) recommendations, Prestressed Code (IS: 1343) and also as per IRC: 18 specifications. The analyzed of box girder using SAP 2000 14 Bridge Wizard and prestressed with parabolic tendons in which utilize full section. The various span/ depth ratio considered to get the proportioning depth at which stresses criteria and deflection criteria get satisfied.

Keywords: Concrete Box Girder Bridge, Prestress Force, Eccentricity, Prestress Losses, Reinforcement, Flexure strength, shear strength, SAP Model.

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By
M.Krishna Kanth
S.Sai Kiran
P.N.Srinivasa Raju
Y.Sri Harsha
(Students, Department of Civil Engineering, Vaddeswaram, Guntur (dist) A.P-522502, India)

K.Prasanthi
(Faculty, Department of Civil Engineering, Vaddeswaram, Guntur (dist) A.P-522502, India)

Abstract
There are a great developments in the recent years like the high-tower buildings, offices, complex structures,or the concrete structures,etc. And the concrete lead for the better performance reducing the self-weight of the structures. As self-weight of the structure is vital for the structural safety. So for this lightweight concrete (LWC) has been used.The use of LWC is increasing for many structural purposes all around the world. LWC is used for fabricated structures which have good thermal insulation,better durability and are lightweight too. The constructional cost is the most important and essential factor for using LWC.The possible advantages of how to design the pre-fabricating structures is briefly scrutinized. The benefits of using this pre-fabricating material , to develop an eco-friendly regime in the environment and to control highly managed disposing of materials is examined.

Keywords: Lightweight concrete, Pre-fabricated materials, Economic Benefits.
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Submitted By
Vinayak Ravindra Supekar.
(National Institute Of Construction Management And Research Center, (Nicmar))

ABSTRACT:
Now days the construction industry in the India is facing one of the major problem that is natural fine aggregate. And court awarded that totally band on excavation of fine aggregate from river because they affect on environment and changing the river direction. (fig.5). Thus the more natural fine aggregate are highly needed to replace with artificial fine aggregate. This paper presentation the study of crack pattern of concrete slab, each size is (500*300*50) mm and replacement of natural fine aggregate with artificial fine aggregate by 20%,40% 60% 100% and also finding the compressive Strength of that concrete cube. And these experiment is carried out maintain temperature 32 0cAnd the according to experimental result show that the replacement of natural sand by artificial sand up to 60% and gives best result that is maximum strength and minimum area of crack.

Key words: – Concrete slab, natural fine aggregate, artificial fine aggregate (grit), crack pattern.
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By
Nagesh Tatoba Suryawanshi
Asst.Professor in Civil Engg. dept
S. B. Patil, College of Engineering, Indapur,(Pune).

Abstract

This Paper reports an experimental study carried out to investigate the use of water-soluble polyvinyl alcohol as self-curing agent. In this study Compressive and tensile strength of self-curing concrete for 7 and 28 days is found out and compared with conventional concrete of similar mix design. The durability of self curing concrete is found out by exposing concrete cubes to chloride environment and effect of the same on strength of cubes is determined by finding out compressive strength of cubes. The results indicated that Water retention for the concrete mixes incorporating self-curing agent is higher compared to conventional concrete mixes, as found by the weight loss with time. The result also showed that compressive, tensile and flexural strength of self curing concrete is found to be higher than conventional concrete.

Key words: Self curing agent, polyvinyl acetate, polyvinyl alcohol, water Retentivity. etc.

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By
S.M. Elzain (School of Applied Earth Sciences, Faculty of Sciences and Technology, Alneelain University, Sudan), S.H. Mohamed (Department of Water Resources, College of Environmental Sciences and Natural Resources, Al Fashir University, Sudan) and Ibrahim A.A.Ibrahim (Water Hydrology and Water Quality Researcher)

Abstract
Hydro-chemical investigations, which are significant for the assessment of water quality have been carried out to study the sources of dissolved ions in hot springs water of some part of Jebel Mara mountain, Sudan. The temperature of hot springs water was varies from 50° C to 60° C. Samples collected from hot springs near Koronga village at Jebel Mara , were analyzed for major solutes and trace elements as part of larger study to characterized the geochemical signature of these ground waters. In this study, four major cations (Ca++, Mg++ , Na+ and K+ ) and three major anions (Cl, SO4 and HCO3) and some trace elements such as (Mn , Zn, Pb , Fe and P) were analyzed in these ground water samples.

This study reveals that most waters taken from hot springs has high values of Hydrogen ion concentration (pH) , electrical conductivity (E.C), high concentrations of total hardness (T.H), total dissolved solids (T.D.S) , bicarbonates (HCO3), sodium (Na) and Magnesium (Mg). High pH, T.D.S, T.H, Na and HCO3 are mainly due to dissolution of these ions from rock bearing minerals of the study area. Normal values of trace elements like Iron (Fe), Copper (Cu), Lead (Pb), Iodine (I) and Zinc (Zn) whereas, high concentrations of Manganese (Mn) (above the recommended values given by W.H.O., 1984). The study classified hot springs waters as Calcium-Magnesium-Sodium Bicarbonate type. Using U.S.D.A.(1954) classification, water has been classified as C2 S1 (medium conductivity-salinity and low sodium content). The discharge values of hot springs measured to be between 2-4 L / S for all hot springs near Koronga village. The thermal waters are associated with Tertiary basalt and heat for these thermal waters is obtained during deep circulation in fracture basalt and is related to volcanic or tectonic activity. This study suggested the geothermal waters of Jebel Mara area are of meteoric origin. Hot springs waters (thermal water) have also been used for medical therapy.

Key words: Darfur region, Jebel Mara Mountain, hot springs, Geochemistry.
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By
Ghalndarzadeh A., Akbari N., Fakher A. from University of Tehran

ABSTRACT
Seismic behavior of quay walls is one of major concerns in earthquake geotechnical engineering field. Among different types of quay walls such as caisson and concrete block walls, deck and pile structures and anchored flexible walls the behavior of flexible walls looks more complicated. In the presented research, a series of shaking table tests were carried out in order to understand the seismic behavior of anchored flexible quay walls. The models were fully instrumented to monitor their behavior during shakings. Displacement of the wall, accelerations in the backfill, excess pore pressures in the soil, bending moment in the wall and tension of tie-rods were measured. By making different relative densities for the backfill and the foundation, different failure modes were observed. It is concluded that the performance of an anchored quay wall is strongly influenced by the occurrence of liquefaction.

Keywords: Anchored flexible quay wall, liquefaction, softening, failure modes
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By
Amir Juma
(Amir Juma is in his final semester of Bachelor of Science in Civil Engineering in Koneru Lakshmaiah University-India. His research interests lie in the field of Self Compaction Concrete.)

E.Rama Sai
(E.Rama Sai is in his final semester of Bachelor of Science in Civil Engineering in Koneru Lakshmaiah University-India. His research interests lie in the field of Self Compaction Concrete.)

D.V.A.K.Prakash
(D.V.A.K.Prakash is in his final semester of Bachelor of Science in Civil Engineering in Koneru Lakshmaiah University-India. His research interests lie in the field of Self Compaction Concrete.)

Md. Shahbaz Haider
(Md.Shahbaz Haider is in his final semester of Bachelor of Science in Civil Engineering in Koneru Lakshmaiah University-India. His research interests lie in the field of Self Compaction Concrete.)

S.Kanakambara Rao
(Associate Professor in Department of Civil Engineering in Koneru Lakshmaiah University-India. He specialized in structural Engineering and research interests lie in the field of Self Compaction Concrete.)

Abstract
Self-compacting concrete, also referred to as self-consolidating concrete, is able to flow and consolidate under its own weight and is de-aerated almost completely while flowing in the formwork. It is cohesive enough to fill the spaces of almost any size and shape without segregation or bleeding. This makes SCC particularly useful wherever placing is difficult, such as in heavily-reinforced concrete members or in complicated work forms.

The objectives of this research were to make a synergic effect of Rice husk Ash (RHA) and Sugar cane bagasse ash(SCBA) incorporated in self compaction concrete in order to increase in strength and a better bonding between aggregate and cement paste, . The mix design used for making the concrete specimens was based on previous research work from literature. The water – cement ratios varied from 0.3 to 0.75 while the rest of the components were kept the same, except the chemical admixtures, which were adjusted for obtaining the self-compactability of the concrete.

All SCC mixtures exhibited greater vaules in compressive strength after being tested, the compressive strength was around 40% greater. In addition, the SCC had a good rheological properties as per the requirements from European standards from economical point of view the pozzolanic replacements were cheap and sustainable.
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