UNIVERSITY OF APPLIED SCIENCES BONN-RHEIN-SIEG

Investigations into the influence of chemical activators and templates on cement hydration

All author

1 Reactions in the early phase of cement hydration

All author

2 Tobermorite structure according to Merlino [16]

3 Amino acids and monomeric additives

4 Ca/Si ratio in the presence of amino acids and monomeric additives

5 Structure solution for the incorporation of alanine (left) and 6-aminohexanoic acid (right) in tobermorite

6 Structure solution for the incorporation of glutamine (left) and imidazole (right) in tobermorite

The strength of hydrated cement and its cohesive properties are determined to a great extent by the structure of the calcium silicate hydrate phases. There is a description of investigations into the crystallization of calcium silicate hydrate (tobermorite) in the presence of various amino acids that lead to significant changes in the elementary cells.

1 Introduction

The most successful ways of reducing the emission of CO₂ during the production of cement are currently based on the use of cement replacement materials and their activation. The investigations and applications have focused on slags, natural pozzolans (trass) and synthetic pozzolans (fly ash, metakaolins and calcined clays) as the cement replacement materials. Low early strengths are often a reason why cement replacement materials are not yet widely used. Familiar options for raising the early strengths and for activation are based on reactions in the early phase of cement...

TEXT Prof. Dr. Steffen Witzleben, University of Applied Sciences Bonn-Rhein-Sieg, Rheinbach/Germany

Issue 02/2013

Formation of intermediate phases during hydration of C3S

1 Introduction The setting of cement is an important technological process. Nowadays, more than 2 billion t of cement are manufactured and processed all around the world. In addition to the...

Issue 4/2019 TECHNISCHE UNIVERSITÄT BERLIN

Accelerating cement hydration with C-S-H seeds

1 Introduction According to the European climate and energy policy, the emission of greenhouse gases is to be reduced by 40?% by 2030 compared to 1990 [1]. The German cement industry contributes...

Issue 02/2024 WUHAN TEXTILE UNIVERSITY

Effect of calcium formate/nano C-S-H composite on early hydration and microstructure of the GGBS-cement system under steam curing

1. Introduction Ground granulated blast-furnace slag (GGBS) is the residue formed by impurities such as SiO2 and Al2O3 and lime in the iron making process, which is collected and water quenched to...

Issue 8/2022 WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY | WUHAN TEXTILE UNIVERSITY | CHINA CONSTRUCTION THIRD BUREAU FIRST ENGINEERING CO., LTD.

Physical-mechanical properties and hydration microstructure of slag powder/cement system with different nanoparticles

1 Introduction Cement is the most used cementitious material in engineering construction in China. Its hardened paste is loose and porous, and the erosive substances can easily enter through the pores...

Issue 06/2013

Studies on guest-ion incorporation in Portland cement – Part 2

4 Aluminum and sulphur guest-ions in alite and belite Limestone is increasingly being used as an additive to Portland cement [22] where a part of it will react with the hydrating aluminate species,...