Research Papers

by
Adama Andrew Yisa (Ministry of Works and Infrastructural Development, Minna, Niger state, Nigeria.)
and
Dr. Y.A. Jimoh (Department of Civil Engineering Faculty of Engineering and Technology University of Ilorin, Ilorin, Nigeria.)

ABSTRACT
Locust Bean Pod Ash (LBPA) was produced by burning Locust Bean Pods in an Incinerator under controlled temperature. The solid residue after the combustion process was sieved using a set IS standard sieves after which the sieved sample was analyzed chemically to determine its constituents. The results of particle size distribution and chemical analysis of Locust Bean Pod Ash revealed that the percentage mass retained on IS sieve 44 µm is 29.6 % while the sum total of the combination of the chemical compounds (Sio2 + Al2O3 + Fe2O3) was 63.57%. These indicate that Locust Bean Pod Ash is pozzolanic in nature.

Keywords
Locust Bean Pod Ash (LBPA), Pozzolan, Chemical analysis, Particle size
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By
Er. Kaushal Kishore ,
Materials Engineer, Roorkee

In about 80% of our construction sites, the water in the concrete mixer is added in a very crude manner either direct from a hoze pipe or by some container without any proper measured quantity. Thus no consideration is given to maintain free Water/Cement ration to its correct specified value resulting production of poor quality of concrete. The addition of mixing water in the concrete mixer with these crude methods always add more water then actually required. This excess water in due course evaporated leaving voids and increasing the porosity of the concrete. Such concrete will have lower strength and also will be not durable.

Therefore it is very important to maintain free W/C ration to its correct value in all the batches of concrete. Free W/C ratio means mixing water added to saturated and surface dry aggregates ie, if the site aggregates are dry extra water is to be added in the mixing water as per the absorption of aggregate, and if the site aggregates contains surface water, this surface water is to be deducted from the mixing water. The weight of aggregates should also be adjusted accordingly. A Concrete Mix Design is reported in standard moisture condition of aggregates and this is saturated and surface dry aggregates. If aggregates are being taken by volume bulking of sand should be taken into consideration.

To solve the construction sites mixing water problems, a simple graduated transparent plastic jar of least count 0.5 ltr, as per drawing should be supplied along with the mixer or may be fabricated at site. This Jar be installed at site near concrete mixer as shown in the drawing. The water may be filled in the jar to the quantity of required gauging water. While mixer is running the measured water in the jar slowly drain in the mixer drum through rubber hoze by opening the valve. If ADMIXTURES are to be used and required to be mixed with the gauging water, this may be mixed with water of the jar.

We at engineeringcivil.com thankful to Sir Kaushal Kishore for publishing his paper on “Water Measuring Jar for Concrete Mixer”.

By
Navaid Ur Rehman,PMP,
M.Eng (Construction Management)
University of Alberta

ABSTRACT
This term paper is prepared as part of the graduate degree requirement. The report consists of two parts:
Part 1: Mold growth in existing buildings
Part 2: Mold during construction

In Part 1 four areas are discussed:
(1) What mold is, how and where it resides and the reason for mold growth (2) Mold health concerns (3) Investigation and evaluation of mold and (4) Mold control if it resides in indoor environments and what should the preventive measures be.

In Part 2 two main areas are discussed: (1) Mold free construction, preventing mold growth before construction and checks during and post construction (2) Toxic Mold Litigation and the number of mold claims have exploded in recent years in the US and Canada.

KEY WORDS
Mold, Health Concern, Risk Factor, Risk Control, Mold free Construction, Construction Claim, Moisture
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By
Preetpal Kaur Ragbir Singh, Assoc. Prof. Dr, Nasir Shafiq
University Technology Petronas, Bandar Seri Iskandar.31750,Tronoh, Perak, Malaysia

Abstract
Design, construction and maintenance requirements of tall buildings and industrial complexes are very different from those applicable for normal building design and construction. For example, for conveying the services and other facilities such as water supply, electricity, air-conditioning and sewerage discharge; a complex network of system routing is provided, which usually align vertically and horizontally and spread throughout the floor area. This complex network is often obstructed by the structural components such as beams, columns and floors and requires to penetrate through such obstruction, which is called the structural penetrations. The size, location and configuration of structural penetration are derived from the type of services, magnitude and speed of facility to be provided. The most prevalent location, size and configuration of structural penetration are always an issue between structural engineers and service or facilities design engineers. This research focuses on the effects of static loading on reinforced concrete beams with openings. This research also studies the prospect of strengthening the beams by using external bonded CFRP in different combinations or arrangement to regain bending capacity that was lost due to the openings. The openings are circular, rectangular, square and elliptical shaped.

Keywords
CFRP Sheets, Large Opening, Static, RC Beam.
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By
S.S.Kolo(1)andy.Ajimoh(2)
Dept.Ofcivilengineering
1. Futminna
2. Unilorin

ABSTRACT
This study present, the Marshall properties of the cold mix asphalt produced with the DPWS modified bitumen were compared with those of the commercial cold mixes in use in Nigeria. The following Stability and flow result were obtained after careful laboratory experiment; for the DPWS modified cold mix Asphalt a stability of 5.8KN and flow of 4mm were obtained when using the normal hot mix method of testing, while stability of 9.58KN and flow of 4.5mm were obtained when air dried method was used. The Portland Emco shows stability of 2.21KN and flow of 3.95mm when it was subjected to test using the normal hot mix method of testing, while a stability of 4.37KN and a flow of 4.85mm were obtained air dried method was used. The Carboncor shows stability of 4.27KN and flow of 5.5mm when it was subjected to test using the normal hot mix method of testing, while a stability of 9.79KN and a flow of 5.5mm were obtained when air dried method was used. The UPM could not be tested for stability when it was subjected to test using the normal hot mix method of testing, but using the air dried method a stability of 1KN and a flow of 6.85mm were obtained. This shows that the modified cold Asphalt has a good strength when subjected to worst condition.

Keywords: Marshall Properties, Stability, DPWS, Cold Asphalt
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By
Shri.Pravin B.Waghmare
Lect. In Civil Engg. Dept.
Acharya Shrimannarayan Polytechnic, Pipri (M)
Wardha (MH)-India

Abstract
Liquid storage tanks are important components of lifeline and industrial facilities. They are critical elements in water supply scheme and fire fighting system, and extensively used for storage and processing of variety of liquid like material such as petroleum product, liquefied natural gas, chemical fluid and wastage of different forms. In this paper, the seismic response of base isolated cylindrical liquid storage tanks is investigated under real earthquake ground motion. The isolation systems considered is elastomeric bearings (without lead core), the specific objectives of the study are to carry out the comparative performance of the tanks with isolation and without isolation (i.e. Fixed tanks) also to investigate the response of the tanks for varying capacity with varying heights. For this study forty tanks of varying heights such as 8m,10m,11m,11.5m,12.5m,14m,16m with varying capacities of 500kl, 265kl, 200kl, 100kl, 50kl are considered. For this a time history analysis has been carried out by using a three time history of varying magnitude with varying peak ground acceleration. It is observed that the base shear of elevated liquid storage tanks supported on shaft is significantly reduced due to isolation. The drift of the tank relation to base of shaft is also significantly reduced due to isolation. The earthquake response of isolated short tanks is relatively more, i.e. Isolation is not effective for stiffer shafts, and however in general, the effectiveness of base isolation is achieved for tall tanks. Although the effectiveness of seismic isolation increases with the increase of bearing flexibility and damping these properties needs to be modified for desired response.

Keywords
Liquid storage tanks, shaft, earthquake ground motion, elastomeric rubber bearing
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By
D.Ishihara, H.Yamada, H.Katsuchi, and E.Sasaki
Yokohama National University

Abstract
There are plans of constructing bridges longer span like Messina strait bridge. This trend causes the necessity of discussing on the problems of instability analysis such as lateral-torsional buckling. However, lateral torsional buckling analysis of long span bridge is not sufficiently taken yet. For that reason, we apply the Abaqus/Standard to solve the high nonlinear problem. The analysis object is Akashi-kaikyo Bridge which is the longest bridge in the world. This paper presents how to analyze the lateral-torsional buckling of long span bridge applying wind load.

Keywords
Lateral Torsional Buckling, Suspension Bridge, Aerodynamics

Introduction
By now, a lot of long span suspension bridges have built and their lengths keep growing. As a result, their girder stiffness is relatively reduced and their strengths for wind force are also decreasing. Therefore, numerous futter analysis and experiments were executed. On the other hand, it is as well as important to investigate the lateral torsional buckling strengths of suspension bridges, but the investigations have never been made for decades. Certainly, we just use Hirai-Okauchi formulation that was proposed around 60’s to confirm the stability against the problem. It contains a theoretical equation and ideal boundary conditions so the application of the formulation is limited. Therefore, the need of modern examination of lateral torsional buckling of suspension bridge is increasing. A long span suspension bridge shows quite nonlinear behavior and shows non linearity when its initial condition and wind load are applied. Therefore it needs some techniques. We present the way of modeling bridges using the structural elements and making initial conditions under gravity. After this we present how to analyze the lateral-torsional buckling of long span bridge applying wind load. The wind load is calculated by the static coefficient of wind force. Finally, the result is showed and the conclusion is presented.
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By
Kevin J. LaMalva
Simpson Gumpertz & Heger, Inc.

Abstract
This research involves a failure analysis of the internal structural collapse that occurred in World Trade Center 5 due to fire exposure alone on September 11, 2001. It is hypothesized that the steel column-tree assembly failed during the heating phase of the fire. Abaqus/Standard was used to predict the structural performance of the assembly when exposed to the fire. Results from a finite element, thermal-stress model confirms this hypothesis, for it is concluded that the catastrophic, progressive structural collapse occurred approximately 2 hours into the fire exposure.

Keywords:
Collapse, Coupled Analysis, Failure, Fire, Heat Transfer, Interface Friction, Structural, Thermal-Stress, World Trade Center (WTC)

1. Background
World Trade Center 5 (WTC 5) was a nine-story building in the World Trade Center complex in New York City, NY (Figure 1). On September 11, 2001, flaming debris from the World Trade Center Tower collapses ignited fires in WTC 5. These fires burned unchecked, ultimately causing a localized interior collapse from the 8th floor to the 4th floor in the eastern section of the building (Figure 2). Debris impact was not a direct factor in this failure; the collapse was caused by fire alone.
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By
Guimer Tarek and Mellas Mekki
Department of Civil Engineering, Mohamed Khider University, Biskra, BP 145, Biskra 07000, Algeria
Tel fax: 033 73 45 28

Abstract
This work aims to study the evolution of the resistance of Portland cement pastes and mortars containing two mineral additions such as calcareous filler and finely crushed slag.

The effects of the addition of two mineral additions to Portland cement pastes are mortars, has been carried to evaluate the evolution of the mechanical resistance as function of the age and the mode of the treatment .This study is a simplified approach to show the contribution of the mineral addition on the development of the mechanical resistance, and the porosity obtained using methanol exchange method. In addition, to confirm this study and based on laboratory test resorts approximate equations were obtained

Keywords: Porosities, cement paste, mortar, mechanical resistance, exchange by methanol.
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by Carl R. Schultheisz, Alan S. Kushner (National Transportation Safety Board), Toshio Nakamura (State University of New York, Stony Brook), Justin Ocel (Federal Highway Administration), William Wright (Virginia Polytechnic Institute and State University) and Min Li (SIMULIA Central)

Abstract
The National Transportation Safety Board (NTSB) investigates accidents to identify the probable cause and to make recommendations that would prevent similar accidents. Following the collapse of the I-35W bridge in Minneapolis on August 1, 2007, the NTSB worked with the Federal Highway Administration, the Minnesota Department of Transportation and other parties with information and expertise, including SIMULIA Central, to determine the circumstances that contributed to the collapse of the bridge, completing the investigation in 15 months. The NTSB concluded that the collapse of the bridge was caused by the inadequate load capacity of gusset plates used to connect the truss members, as a result of an error by the bridge design firm, Sver-drup & Parcel and Associates, Inc. The loading conditions included a combination of (1) substantial increases in the weight of the bridge caused by previous bridge modifications, and (2) the traffic and concentrated construction loads on the bridge on the day of the collapse. Evidence from the collapsed bridge structure, engineering evaluations of the design, and results from the finite element analyses used to support the investigation are reviewed.

Keywords: Bridge Collapse, Gusset Plate, Plasticity, Instability, Riks, Fasteners.
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