This paper presents the effect of Sodium Chloride (NaCl) on Conventional Concrete (Silica Fume Based M30 Grade Concrete). The Silica Fume Based M30 Grade Concrete was prepared by adding NaCl concentrations of 0.5,2,4,6,8,10 and 12 g/l i n deionised water. In addition to this, control specimen was prepared with deionised water (without NaCl) for the purpose of co mpari son . The tensile strength...

Without using strong alkaline solution or ordinary Portland cement, a new structural binder consisting of fly ash and hydrated lime was hardened through an intensified pozzolanic reaction. The main experimental variables are the addition of silica fume and initial thermal treatment (60 °C for 3 days). A series of experiments consisting of mechanical testing (compressive and flexural strength, m...

Neural networks have recently been widely used to model some of the human activities in many areas of civil engineering applications. In the present paper, artificial neural networks (ANN) for predicting compressive strength of cubes and durability of concrete containing metakaolin with fly ash and silica fume with fly ash are developed at the age of 3, 7, 28, 56 and 90 days. For building these...

The present investigation revealed the effect of using silica fume and copper slag as a partial replacement of cement and fine aggregate, respectively on the mechanical properties of the concrete. Due to the depletion of natural sand resource worldwide with the increment of industrial waste, simultaneously, partial replacements of fine aggregate with copper slag have been attempted. Therefore, ...

A series of concrete slabs were cast with 0, 7, and 12% by mass silica fume replacement of cement at W/CM = 0.35, 0.40, and 0.45. After either moist or steam curing, a variety of chloride resistance tests were performed. These included AASHTO T259, modified T259, T277, as well as several bulk diffusion tests and sorptivity tests. Results indicate that the use of properly dispersed silica fume r...

Recently, 3D printing technology has become more popular in the field of construction. For extrusion-based concrete (3DCP) process, cementitious material needs to be strong and flowable enough ensure buildability pumpability. Nanostructured silica, a kind additive, been used modify 3DCP meet these requests. However, most previous studies focused on effect nanostructured silica rheological prope...

Sulfate attack is a series of physico-chemical reactions between hardened cement paste and sulfate ions. Sulfate ion penetration into the hydrated cement results in the formation of voluminous and deleterious phases such as gypsum and ettringite which are believed to cause deterioration and expansion of concrete. Concrete deterioration due to sulfate attack depends on many parameters, however, ...

Solids Liquids Gases/vapours Asbestos dust Sprayed droplets Ammonia Engine exhaust particles Paints Carbon monoxide Lead dust and fume Pesticides Carbon dioxide Silica dust Power coating mix Freon’s Welding fume Liquid jetting Helium Shot blasting dust Sewage water Nitrogen Wood dust Mercury vapour Smoke Mists Solvent vapours Fungal spores Chrome acid Engine exhaust gases Bacteria Cutting fluid...

In this paper, we model the underlying probability density function (PDF) of the speech line spectral frequencies (LSF) parameters with a Dirichlet mixture model (DMM). The LSF parameters have two special features: 1) the LSF parameters have a bounded range; 2) the LSF parameters are in an increasing order. By transforming the LSF parameters to the ΔLSF parameters, the DMM can be used to model ...

colloidal nanosilica is currently being produced by various methods which are mainly high energy intensive and/or not environmentally friendly. it is therefore essential to develop new energy-efficient and environmentally friendly technologies. this paper introduces a new ultrasound assisted route based on alkali leaching of silica fume for synthesis of colloidal silica nanoparticles. the ef...