Analysis of alkali-activated mineral wool-slag binders: evaluating the differences between one-part and two-part variations

Two synthesis pathways (one- and two-part) in alkali-activated binders were compared using ground granulated blast furnace slag (GGBFS), mineral wool (MW) activated using dry and liquid alkali activators with similar Na₂O/SiO₂ modulus. The effect of activator type on reaction kinetics, strength development, setting times...

Statistical mixture design for carbide residue activated blast furnace slag foamed lightweight concrete

Carbide residue activated blast furnace slag is a relatively new kind of eco-friendly construction materials. This work addresses the design of foamed lightweight concrete as road embankment material using such material. A statistical mixture design approach was adopted to assess the influence of each ingredient as well as the interaction...

Fresh and hardened properties of alkali-activated slag concrete: The effect of fly ash as a supplementary precursor

The present study explores the possibility of replacing blast furnace slag (BFS) with coal fly ash (FA) to produce alkali-activated material (AAM) concrete with hybrid precursors. With an increased FA replacement ratio, the reaction kinetics, fresh and hardened properties of AAM mixtures have been investigated. The retardation effect on the...

Rheology of alkali-activated slag pastes: New insight from microstructural investigations by cryo-SEM

This study aims to interpret the early-stage rheology of alkali-activated slag (AAS) paste from microstructure perspectives. The microstructures visualized by cryogenic scanning electron microscopy (cryo-SEM) revealed the essential distinction between hydroxide and silicate-activated slag pastes. The hydroxide-based mixture showed typical...

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Ultra-high performance concrete (UHPC) is an innovative cement-based composite with high mechanical performance under tensile and compressive loads, extremely low permeability, and excellent durability. Because of these features, UHPC has the potential to contribute to the development of new architectural perspectives and structural systems...

RILEM TC 247-DTA round robin test: carbonation and chloride penetration testing of alkali-activated concretes

Many standardised durability testing methods have been developed for Portland cement-based concretes, but require validation to determine whether they are also applicable to alkali-activated materials. To address this question, RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ carried out round robin testing of carbonation...

Effect of supplementary materials on the autogenous shrinkage of cement paste

In recent years more and more attention has been given to autogenous shrinkage due to the increasing use of high-performance concrete, which always contains supplementary materials. With the addition of supplementary materials-e.g., fly ash and blast furnace slag-internal relative humidity, chemical shrinkage and mechanical properties of...

Modelling of autogenous shrinkage of hardening cement paste

In recent decades, several simulation models have been proposed to predict autogenous shrinkage of cementitious systems. In most of these models, however, only the elastic deformation caused by self-desiccation of the hydrating cement paste is considered. In fact, cement paste is not an ideal elastic material. Also the time-dependent...

RILEM TC 247-DTA round robin test: mix design and reproducibility of compressive strength of alkali-activated concretes

The aim of RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ is to identify and validate methodologies for testing the durability of alkali-activated concretes. To underpin the durability testing work of this committee, five alkali-activated concrete mixes were developed based on blast furnace slag, fly ash, and flash-calcined...

Evaluation of RRSB distribution and lognormal distribution for describing the particle size distribution of graded cementitious materials

Graded blended cement made of graded Portland cement (PC), blast furnace slag (BFS) and fly ash (FA) is attractive for cement production. For manufacturing graded blended cement, a suitable mathematical expression should be introduced to describe the particle size distribution (PSD) of its components and control the quality of graded blended...