Mortar serves as the basis for the workability properties of self-compacting concrete (SCC) and these properties could be assessed by self-compacting mortars (SCM). In fact, assessing the properties of SCM is an integral part of SCC design. The objective of this study was to evaluate the effectiveness of various mineral additives and chemical admixtures in producing SCMs. For this purpose, four mineral additives (fly ash, brick powder, limestone powder, and kaolinite), three superplasticizers (SP), and two viscosity modifying admixtures (VMA) were used. Within the scope of the experimental program, 43 mixtures of SCM were prepared keeping the amount of mixing water and total powder content (portland cement and mineral additives) constant. Workability of the fresh mortar was determined using mini V-funnel and mini slump flow tests. The setting time of the mortars, were also determined. The hardened properties that were determined included ultrasonic pulse velocity and strength determined at 28 and 56 days. It was concluded that among the mineral additives used, fly ash and limestone powder significantly increased the workability of SCMs. On the other hand, especially fly ash significantly increased the setting time of the mortars, which can, however, be eliminated through the use of ternary mixtures, such as mixing fly ash with limestone powder. The two polycarboxyl based SPs yield approximately the same workability and the melamine formaldehyde based SP was not as effective as the other two.

The effect of chemical admixtures and mineral additives on the properties of self-compacting mortars

Disposal of fly ash (FA) resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA) as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a partial replacement of cement in traditional paste/mortar/concrete mixtures based on Portland cement (PC). Fresh properties, mechanical properties, abrasion resistance, thermal properties, drying shrinkage, porosity, water absorption, sorptivity, chemical resistance, carbonation resistance and electrical resistivity of paste/mortar/concrete mixtures containing HVFA (⩾45%) as cement replacement have been reviewed. Furthermore, additives used to improve some properties of HVFA system have been reviewed.

A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

Effect of different superplasticisers on the physical and mechanical properties of cement grouts

Optimisation of rheological parameters and mechanical properties of superplasticised cement grouts containing metakaolin and viscosity modifying admixture

Experimental study on performance of cement-based grouts admixed with fly ash, bentonite, superplasticizer and water glass

Basic rheological and mechanical properties of high-volume fly ash grouts

Properties of microfine cement grouts at 4 °C, 10 °C and 20 °C

This paper presents an experimental study on the investigation of concrete properties by guided and surface wave nondestructive testing. Applications were made on two large slabs simulating homogeneity and layering in concrete, respectively. An efficient nonintrusive method was used to evaluate the concrete quality by solving the modal propagation problem of Lamb guided waves and Rayleigh surface waves. Lamb waves were used to determine the Poisson's ratio and the Young's modulus of the concrete slabs. Rayleigh waves were identified using Lamb wave fundamental-modes; thereafter, the inverse problem of Rayleigh waves was solved to evaluate the variation of shear wave velocity with depth and thus characterize the layered slab. The obtained results demonstrate the high potential of this tool that can easily be used for in-place assessment of concrete structures.

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Assessment of Concrete Slab Quality and Layering by Guided and Surface Wave Testing

Visual inspection of rock bolts could give some indications on their condition and performance. However, it might be misleading because most of the rock bolts are embedded in concrete or gr...

Kaveh Saleh

Papers

Basic rheological and mechanical properties of high-volume fly ash grouts

Properties of microfine cement grouts at 4 °C, 10 °C and 20 °C

Assessment of Concrete Slab Quality and Layering by Guided and Surface Wave Testing

Assessment of Corroded Rock Bolts with Pulse Echo Tests

Application of nondestructive evaluation techniques on concrete dams