By incorporating lightweight expanded polystyrene aggregate particles in a conventional highstrength concrete mixture, its density could be adjusted to any desired level. The adjusted density concrete can be expected to have reduced strength and stiffness the permeability of concrete would not be affected since the non-water absorbing polystyrene aggregate particles are dispersed randomly in a ...

lateral resistance of railway track is one of the most important parameters in lateral stability. this parameterdepends!on the conditions of different components of ballasted railway track (such as density of ballast layer,sleeper spacing, type of sleeper, etc.). from this perspective, type of sleeper has an important effect on lateralresistance. however in some conditions, in technical and eco...

INTRODUCTION Porous concrete, especially Aerated Autoclaved Concrete (AAC) was first developed by a Swedish engineer between the years 1920 and 1932 [1]. He was searching for a material with the properties of wood, but without the disadvantages of wood. Near the end of World War II, AAC became widely used. Vast areas of cities and industries lay in waste and tremendous rebuilding became necessa...

The presence of capillary pores and air voids influences concrete permeability to a large extent. Concrete density is inversely proportional to its porosity. The ingress of aggressive agents into the pore structure is responsible for various durability problems in concrete structures. Therefore, a durable concrete should have low permeability. Permeability of concrete increases with the increas...

The construction industry generates a considerable amount of waste. Faced with this undesirable situation, the ready-mix concrete sector, in particular, has invested energy and resources into reusing its own waste in its production process as it works towards the goal of more sustainable construction. This study examines the feasibility of incorporating two types of concrete waste, which curren...

The susceptibility of structural concrete to early-age cracking depends on material composition, methods of processing, structural boundary conditions, and a variety of environmental factors. Computational modeling offers a means for identifying primary factors and strategies for reducing cracking potential. Herein, lattice models are shown to be adept at simulating the thermal-hygral-mechanica...

This paper presents the residual mechanical properties of concrete made with crushed bricks and clay roof tile aggregates after exposure to high temperatures. One referent mixture and eight mixtures with different percentages of replacement of natural aggregate by crushed bricks and roof tiles are experimentally tested. The properties of the concrete were measured before and after exposure to 2...

We analyze a signature scheme described in a recent Internet Draft, and highlight a variant (based on prior work of Micali and Leighton) that offers improved concrete security.