This paper summarizes the test results of an extensive research program sponsored by the US Transportation Research Board of the National Research Council to examine the behavior of high-strength concrete rectangular columns subjected to concentric and eccentric loading conditions. The variables considered in this investigation were concrete strength ranging from 7.9 ksi (55 MPa) to 16.5 ksi (1...

This paper presents a new model for predicting the compressive strength of steel-confined concrete on circular concrete filled steel tube (CCFST) stub columns under axial loading condition based on Artificial Neural Networks (ANNs) by using a large wide of experimental investigations. The input parameters were selected based on past studies such as outer diameter of column, compressive strength...

Plastic concrete consists of aggregates, cement, water and bentonite, mixed at a high water cement ratio, to produce a ductile material. It is used for creating an impermeable barrier (cut-off wall) for containment of contaminated sites or seepage control in highly permeable dam foundations. The effects of water to binder ratio and clay dosage on mechanical properties of plastic concrete were i...

Many concrete structures are required to have sufficient abrasion resistance, such as dams, canals, roads and floors. The abrasion resistance of concrete may be defined as its ability to resist being worn away by rubbing. Compressive strength and aggregate type are also important factors affecting the abrasive behaviour of concrete. However, very little information on the properties of haematit...

abstract  introduction: recently uses of medium and high energy x-rays has been increased in iran and radiotherapy centers along with a variety of accelerators have been installed in some provinces. in the other hand there is no sufficient skill in designing and making radiotherapy treatment rooms. this study was conducted to evaluate the efficacy of different mixtures of barite concrete for sh...

This paper presents the results of an experimental study on the effects of elevated temperature on compressive and flexural strength of Normal Strength Concrete (NSC), High Strength Concrete (HSC) and High Performance Concrete (HPC). In addition, the specimen mass and volume were measured before and after heating in order to determine the loss of mass and volume during the test. In terms of non...

Prediction of compressive strength of concrete is very useful for economic constructions. The compressive strength can be estimated after 28 days of casting the specimen cubes or may be predicted based on the quantum and quality of ingredients used in making the concrete. When the first one requires a 28-day time, the second one does have problem of accuracy. Hence, a hybrid model is proposed i...

Concrete is a heterogeneity material consisting of mortar and aggregate in meso scale. Evaluation of fracture process in this scale is useful to clarify the material characteristics of concrete. However, analytical approach in this scale has not been carried out enough yet. And in meso scale, mortar-aggregate interface is the weakest part in concrete so that it is considered that its material p...

The aim of this study is to evaluate the moisture effect on the strength of concrete specimens that has completely cured. This study is also aimed to develop relations that can be used to determine the properties of concrete with different moisture contents that are normally experienced in outside conditions. Numerous compressions and split tensile tests are performed. In order to better unders...

Some Problems on High Strength Concrete for Prestressing by Kanji YAMAZAKI (Research Laboratory of Nihon Cement Co., Ltd., Tokyo) This paper describes some problems on high strength concrete studied in our laboratory in recent years. Summary of this report is as follows: (1) In order to make high strength concrete for prestressing, it is necessary to lower the water-cement ratio. But, in the ca...