Utilization of Lightweight Tetrapod Aggregate Produced from a High Calcium Fly Ash in Civil Engineering Applications

Due to the increasing volumes of fly ash production in some countries that depend on coal for running their thermal power plants, new utilization areas must be found. One of these areas is to utilize large volume applications such as the production of special shape aggregate (tetrapod) to be used in different geotechnical applications and highway construction. This is beneficial in solving the disposal problem of fly ash as well as making economical use of a mineral resource. To achieve these goals, fly ash was utilized in producing tetrapod shape lightweight aggregate by pressing into a specially designed mold. Pre to the production of tetrapods, regular lightweight fly ash aggregates were produced, cured and tested. Test results on the regular lightweight fly ash aggregates were implemented in the production of tetrapods. Optimization of lime content showed that five per cent by weight lime addition to fly ash had the best performance. Tests were conducted on the cured tetrapods in order to determine their mechanical and physical properties. Absorption and other properties were improved by surface treatment with water glass and heating

A comparative analysis of the fracture and fatigue properties of asphalt concrete and sulphlex

Typescript (photocopy).A new approach to the characterization of pavement mixtures' toughness based on the J integral concept was developed. The fracture mechanics approach was used to compare fatigue and fracture characteristics of new plasticized sulfur binders with asphalt concrete. Crack growth rates were correlated with the J*-parameter which is an energy line integral. Crack growth rate tests were conducted on the TTI overlay tester. Fatigue characteristics were determined by laboratory experiments on the conventional beam fatigue tests. The variation of fatigue and crack resistance characteristics with temperature, rest time, type of material, displacement magnitude, displacement rate and thickness was examined. The results of the experimental analysis supported the notion of geometry independence of this approach. The results showed that crack growth rate correlated with the J* integral, while other parameters (K) failed to adequately characterize crack growth rate. A new concept for the prediction of crack resistance life based on material toughness as characterized by the J* and the critical energy release rate (J*(,IC)) was outlined.A procedure for estimating a shift factor between laboratory and field results that consider the effects of both strain and crack recovery was developed

A comparative analysis of the fracture and fatigue properties of asphalt concrete and sulphlex

Typescript (photocopy).A new approach to the characterization of pavement mixtures' toughness based on the J integral concept was developed. The fracture mechanics approach was used to compare fatigue and fracture characteristics of new plasticized sulfur binders with asphalt concrete. Crack growth rates were correlated with the J*-parameter which is an energy line integral. Crack growth rate tests were conducted on the TTI overlay tester. Fatigue characteristics were determined by laboratory experiments on the conventional beam fatigue tests. The variation of fatigue and crack resistance characteristics with temperature, rest time, type of material, displacement magnitude, displacement rate and thickness was examined. The results of the experimental analysis supported the notion of geometry independence of this approach. The results showed that crack growth rate correlated with the J* integral, while other parameters (K) failed to adequately characterize crack growth rate. A new concept for the prediction of crack resistance life based on material toughness as characterized by the J* and the critical energy release rate (J*(,IC)) was outlined.A procedure for estimating a shift factor between laboratory and field results that consider the effects of both strain and crack recovery was developed

Railways in Jordan: Possible Implementation in Public Transportation.

In the last few years Jordan has witnessed significant economic and social changes that led to serious challenges in the transportation sector. This paper investigates the possibility of recruiting railway services as one of the strategies to improve public transportation and face the ever increasing traffic problems.A rehabilitation project of existing railways is presented in comprehensive details starting with an evaluation of the current situation and defining the main requirements to implement the project. The project considers both passengers and freight possible improvements can be gained by applying the railway services.Through the detailed review of the suggested project’s benefits, the recommendations came to go for the rehabilitation project, especially under the current budget limitations in Jordan and current political events in the neighbor countries