APPLICATION OF RADAR AND ULTRASONIC PULSE ECO FOR TESTING FOR CONRETE STRUCTURES

Introduction

Non-destructive testing in reinforced concrete structure is one of the essential task for
estimating or assessing the quality. This includes identification of defects such as
honeycombs, voids, cracks, etc., and, thickness measurement, location of reinforcements,
ducts, etc., The Ground Penetrating Radar (GPR) technique is a very effective method for
investigating the integrity of concrete, thickness measurement, reinforcement identification in concrete structures (1-4). The Ultrasonic Pulse Echo is a one-sided technique which can be used effectively for the thickness measurement, localization of reinforcement and ducts, and the characteristics of surface cracks (5-6). The main aim of the paper is to demonstrate the application of radar and ultrasonic pulse-echo testing techniques in measuring the thickness, identification of reinforcements, defects in concrete and other embedment’s.

for more...>  http://seminarprojects.com/Thread-application-of-radar-and-ultrasonic-pulse-echo-for-testing-concrete-structures-pdf

SELF COMPACTING CONRETE

Self-Consolidating Concrete (SCC) is a rapidly developing research area with literally hundreds of published papers. This technical bulletin provides a “primer” on SCC. It is not an all-encompassing document but is an introduction to the subject providing general information.

What is SCC?

Self-Consolidating Concrete has properties that differ considerably from conventional slump concrete. SCC is highly workable concrete that can flow through densely reinforced and complex structural elements under its own weight and adequately fill all voids without segregation, excessive bleeding, excessive air migration (air-popping), or other separation of materials, and without the need for vibration or other mechanical consolidation.

for more...>  http://www.na.graceconstruction.com/custom/concrete/downloads/tb_1500b.pdf

BAMBOO AS BUILDING MATERIAL

Building with bamboo looks back on an ancient tradition in the regions in which plant grows in abundance, such as South America, Africa and, in particular, in South-EastAsia. Bamboo is one of the oldest construction materials.

Bamboo has durable rootstocks, the rhizomes. After a seedling has produced the first rhizome, the differentiated rhizome system will begin to develop. Its circumferential and longitudinal growth increases annually. It is only after twelve and more years that canes of full thickness and height will be produced. According to the type of branching of the rhizomes the main group of the bamboos is called monopodial, whereas the other group is called sympodial.

for more....>  http://bambus.rwth-aachen.de/eng/PDF-Files/Bamboo%20as%20a%20building%20material.pdf

RAIN WATER HARVESTING

Rainwater harvesting is a technology used for collecting and storing rainwater from rooftops, the land surface or rock catchments using simple techniques such as jars and pots as well as more complex techniques such as underground check dams. The techniques usually found in Asia and Africa arise from practices employed by ancient civilizations within these regions and still serve as a major source of drinking water supply in rural areas. commonly used systems are constructed of three principal components; namely, the catchment area, the collection device, and the conveyance system.

for more...>  http://www.gdrc.org/uem/water/rainwater/introduction.html

USE OF PLASTIC WASTE IN CONCRETE

Plastic bags which are commonly used for packing, carrying vegetables, meat etc creates a serious environmental problem. Plastic bag last in environment up to 1000 years because of plastic bag last so long the number of plastic bag accumulated increases each year. Disposal of large quantity of plastic bag may cause pollution of land, water bodies and air. The proposed concrete which is made up by adding plastic in concrete may help to reuse the plastic bag as one of the constituent’s material of concrete, to improve the certain properties of concrete. The properties of concrete containing varying percentages of plastic were tested for compressive strength and Split tensile strength and shows that an appreciable improvement in tensile strength of concrete can be achieved by introducing cut pieces of plastic bags.

for more....> http://www.technicaljournalsonline.com/ijaers/VOL%20I/IJAERS%20VOL%20I%20ISSUE%20III%20APRIL%20JUNE%202012/137.pdf

SILICA FUME IN CONCRETE

The American Concrete Institute (ACI) defines silica fume as “very fine non-crystalline silica produced in electric arc furnaces as a by-product ofthe productions of elemental silicon or alloys containing silicon”  (ACI 116R).  It is usually a gray colored powder, somewhat similar to portland cement or some fly ashes.  Silica fume is usually categorized as a supplementary cementitious material.  This term refers to materials that are used in concrete in addition to portland cement.

 Silica fume is frequently referred to by other names :

1. Condensed silica fume

2. Microsilica

 3.Volatilized silica

Silica fume is a by-product of producing silicon metal or ferrosilicon alloys in smelters using electric arc furnaces.  These metals are used in many industrial applications to include aluminum and steel production, computer chip fabrication, and productions of silicones, which are widely used in lubricants and sealants.  While these are very valuable materials, the by-product silica fume is of more importance to the concrete industry.  

for more.....> http://www.bigfreshcontrol.com/documents/act_documents/10101_Silica_Fume_Definition.pdf

GLASS FIBER REINFORCED CONRETE

Glass fiber reinforced composite materials consist of high strength glass fiber embedded in a cementitious matrix. In this form, both fibers and matrix retain their physical and chemical identities, yet they produce a combination of properties that can not be achieved with either of the components acting alone. In general fibers are the principal load-carrying members, while the surrounding matrix keeps them in the desired locations and orientation, acting as a load transfer medium between them, and protects them from environmental damage.”

GFRC is a form of concrete that uses fine sand, cement, polymer (usually an acrylic polymer), water, other admixtures and alkali-resistant (AR) glass fibers. Many mix designs are freely available on various websites, but all share similarities in ingredient proportions.

GFRC History and Application

GFRC was originally developed in the 1940’s in Russia, but it wasn’t until the 1970’s that the current form came into widespread use.

Commercially, GFRC is used to make large, lightweight panels that are often used as façades. These panels are considered non-structural, in that they are designed to support their own weight plus seismic and wind loadings, much in the way glass window curtain walls are designed. The panels are considered lightweight because of the thinness of the material, not because GFRC concrete has a significantly lower density than normal concrete. On average it weighs about the same as ordinary concrete on a volume basis.

For more...> http://www.concretecountertopinstitute.com/modules/smartsection/item.php?itemid=57