Alkali-activated materials

Geopolymer concrete: A review of some recent developments

A review of the multi-component utilisation of coal fly ash

Advances in understanding alkali-activated materials

The development of new, sustainable, low-CO2 construction materials is essential if the global construction industry is to reduce the environmental footprint of its activities, which is incurred particularly through the production of Portland cement. One type of non-Portland cement that is attracting particular attention is based on alkali-aluminosilicate chemistry, including the class of binders that have become known as geopolymers. These materials offer technical properties comparable to those of Portland cement, but with a much lower CO2 footprint and with the potential for performance advantages over traditional cements in certain niche applications. This review discusses the synthesis of alkali-activated binders from blast furnace slag, calcined clay (metakaolin), and fly ash, including analysis of the chemical reaction mechanisms and binder phase assemblages that control the early-age and hardened properties of these materials, in particular initial setting and long-term durability. Perspectives fo...

Geopolymers and Related Alkali-Activated Materials

A geopolymer concrete prepared by predicting a mechanical property of a geopolymer concrete formed with each of a plurality of fly ash materials, selecting as a source material for the geopolymer concrete one of the fly ash materials that yields a predicted value of the mechanical property that is equal to or greater than a target value for the mechanical property, and mixing the fly ash source material with an alkaline activator solution, a fine aggregate, and a coarse aggregate. The prediction of the mechanical property includes measuring one or more properties of each of the plurality of fly ash materials, calculating predicted values of the mechanical property for geopolymer concretes formed with each of the plurality of fly ash materials using a predetermined equation relating the one or more properties of the plurality of fly ash materials to predicted values of the mechanical property of the geopolymer concrete.

Method for geopolymer concrete

A steerable ground piercing tool includes an elongated outer housing having a lengthwise extending bore and an inner assembly at least in part disposed within the outer housing. The inner assembly includes a rotatable chisel having a longitudinally extending shaft at least in part disposed within the housing bore. The chisel has a first end defining an asymmetric tip and a second end defining a first impact surface for receiving a reciprocating action impact to drive the tool through the ground. The inner assembly further includes a conversion mechanism to selectively convert upon activation thereof at least a first portion of the reciprocating action imparted to the first impact surface into combined reciprocation and rotation of the tool.

Steerable ground piercing tools

Optimization and Characterization of Geopolymer Mortars using Response Surface Methodology

Long-Term Monitoring and Analysis of Full Scale Concrete Pipe Test Beds

This paper focuses on developing a rapid and cost effective evaluation methodology for the condition assessment of culverts to estimate their remaining service life. Nondestructive inspection methods are selected based on their reliability and effectiveness. A synthesis of current and emerging non-destructive technologies (NDT) for culverts assessment management is presented. The information presented intends to serve as a database for a generalized algorithm for selecting a NDT scheme for condition assessment of culverts and their embedment.

Erez N. Allouche

Papers

Method for geopolymer concrete

Steerable ground piercing tools

Optimization and Characterization of Geopolymer Mortars using Response Surface Methodology

Long-Term Monitoring and Analysis of Full Scale Concrete Pipe Test Beds

Evaluation of Non-Destructive Methods for Condition Assessment of Culverts and Their Embedment