this research paper presents the use of wasteful supplementary cementitious materials like fly ash and silica fume to conserve the cement used in concrete. the cement industry is one of the major producers of greenhouse gases and an energy user. in this study, portland cement was used as a basic cementitious material. fly ash and silica fume were used as the cement replacements by weight. the r...

The effect of moisture absorption and high temperature on the compressive strength of unidirectional IM7/977-2 carbon/epoxy resins have been investigated experimentally. The specimens were divided into 4 groups, and tested under 4 different conditions by varying the testing temperature and moisture parameters. The fiber orientation selected were 0o, ±45o and 90o...

it has been shown that geopolymerization can transform a wide range of waste aluminosilicate materials into building materials with excellent chemical and physical properties such as fire and acid resistance. in this research work, geopolymerization of construction waste materials with different alkali-activators based on combinations of na2sio3 and naoh has been investigated. a number of syste...

This paper reports the strength behaviour of concrete containing three types of recycled polyethylene terephthalate (PET) aggregate. Results are also analysed to determine the PET-aggregate’s effect on the relationship between the flexural and splitting tensile strengths and compressive strength and to know whether the relationships between compressive strength and other strength characteristic...

In this paper, regression analysis method i.e., traditional method and ridge regression is applied on the dataset collected for the prediction of compressive strength of concrete. When regression analysis is applied and data set is increased or decreased, the regression coefficients have drastically changed their values like the negative coefficients changed to positive or vice versa. So, tradi...

Results: The experiment results indicate that the type of recycled aggregate and its replacement ratio have significant effects on the freezethaw performance. The cubic compressive strength of recycled aggregate concrete is overall slightly lower than that of normal concrete. After 100 freeze-thaw cycles, the compressive strength decreases and the reduction extent increases with increasing repl...

OBJECTIVES To assess compressive strength and effect of duration after photoactivation on the compressive strength of different dual cure bulk fill composites. METHODS Seventy-two disc shaped (4x10mm) specimens were prepared from three dual cure bulk fill materials, ZirconCore (ZC) (n=24), MulticCore Flow (MC) (n=24) and Luxacore Dual (LC) (n=24). Half of the specimens in each material were t...

The aim of this research was to study the effect of various water-to-cement ratio on the properties of pervious concrete. Tests were carried out to find the optimum water-to-cement ratio that gives a high compressive strength with acceptable permeability. The tests of fresh density, compressive strength at 7days, porosity and water permeability for four mixes of pervious concrete with various w...

In this chapter, we will present the precursors and manufacturing of carbon fibers. Among the precursors used for the production of carbon fibers, polyacrylonitrile (PAN)-based and pitch-based precursors are the most important. A significant amount of work has been done on relating the fiber structure to the properties and translating that relationship into production for either reducing cost o...