Bricks manufactured from dried sludge collected from an industrial wastewater treatment plant were investigated. Results of tests indicated that the sludge proportion and the firing temperature were the two key factors determining the brick quality. Increasing the sludge content results in a decrease of brick shrinkage, water absorption, and compressive strength. Results also showed that the br...

different additives have been considered to improve stabilization of the engineering properties of fine-grained soil. the present study investigated the effect of the addition of sewage sludge ash on the compressive strength of clay soil at optimum moisture content and under saturated conditions. the four treatments tested were the addition of 0%, 5%, 10% and 15% sewage sludge ash to clayey soi...

this paper introduces an innovative partially destructive method, called “twist-off”, for the assessment of in situ concrete strength. in this method a 40mm diameter metal probe is bonded to a concrete surface by means of a high strength epoxy resin adhesive. to measure the concrete compressive strength, a torque is applied using an ordinary torque-meter and the maximum shear stress at failure ...

Abstract: The linear expansion, early-age compressive strength and setting times of the binary mixtures of gypsum and Portland cement clinkers of relatively low C3A-contents were investigated. For this reason, type 1, 2, and 5 of Portland cement-clinkers were selected and a number of binary mixtures were designed. At relatively lower percentages of gypsum (about 5%), the early strength behavior...

Metakaolinite-based geopolymer has been synthesized at about 25 °C from metakaolin which has been calcined in different temperatures (600-900 °C) and different Na2O/SiO2 ratio activator (0.3-1.1). Compressive strength and microstructure of cement pastes after 7-28 days curing at ambient temperature were measured. Compressive strength tests on the samples showed that the sample made with calcine...

In this study, the co-operation of steel and concrete in composite columns is considered. Using numerical modeling to study the behavior of these sections, a new type of sections, namely Concrete Filled Double-Skin steel Tubular (CFDST) columns, is introduced. The parameters and techniques that influence the numerical simulation that bring this modeling closer to...

The high performance concrete is a highly complex material that consists of cement, water, blast furnace slag, super-plasticizer, coarse and fine aggregate. All of the materials play a certain role in the compressive strength of concrete. Combined with the information about age, the compressive strength of concrete is determined by eight attributes: 1. Cement (kg/m!) 2. Fly ash (kg/m!) 3. Blast...