Poly (urea-formaldehyde) (PUF) shelled dicyclopentadiene (DCPD) microcapsules were prepared by in-situ polymerization technology for self-healing concrete applications. It’s found, during the process, sodium dodecyl benzene sulfonate (SDBS) behaves better in emulsification of DCPD than other surfactant of sodium lauryl sulfate (SLS) and styrene maleic anhydride copolymer (SMA), and the addition...

River sand is becoming increasingly scarce. As a result, an alternative material required to replace river in order save sand. In the construction of quality concrete, artificial aggregate now frequently employed as substitute for Coconut fibre ash (CFA) obtained from prevalent India. Partially replacing (fine aggregate) with presaturated CFA self curing purpose presented paper. Fine aggregates...

Concrete is one of the most popular construction materials in the world. Chemical admixtures are ingredients added to concrete to enhance its properties. However, most chemical admixtures on the market today are expensive, thereby making them out of reach for small consumers of concrete. In Africa, use of chemical admixtures is rare despite the harsh weather conditions. In the current study, Gu...

Silica fume (SF) and Metakaolin are cementitious materials used as admixtures to produce high strength concrete and to reduce the permeability. Also, Silica fume is used to make durable concrete structures in combination with ordinary Portland cement. In places where insufficient or poor curing concrete structures like sea shores, underground structures which undergo severe loss of compressive ...

In the present study, effect of pozzolanic material (Metakaolin and Silica fume) is studied through compressive and Flexural strength in cement concrete. Metakaolin and silica fume area used as cement replacement materials at 5%, 10% and 15% by mass keeping water–cement ratio as 0.42 Compressive and Flexural strength were observed after 7 and 28 days of curing. Silica fume is a by products resu...

As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are t...

Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal ...

A one-sided, nondestructive, ultrasonic technique for monitoring the setting and hardening process of concrete has recently been developed. The technique is based on monitoring the reflection coefficient of ultrasonic transverse waves at the surface of a laboratory scale hardening concrete in steel molds. The technique has been shown to reliably estimate the rate of strength gain of concrete un...

Self-Compacting Concrete Originally developed in Japan, SCC technology was made possible by the much earlier development of Superplasticisers for concrete. To compare the performance of SCC with Fly Ash 20%, Silica Fume 10%, Rice Husk Ash (5%, 10%, and 15%) as a partial replacement of cement, due to the high increase in construction which has brought a heavy demand for ingredients of concrete s...