Title: 1. Introduction
Author(s): H. W. Reinhardt, E.A.B. Koenders
Paper category : book
Book title: Advanced Testing of Cement-Based Materials during Setting and Hardening - Final Report of RILEM TC 185-ATC
Editor(s): H.W. Reinhardt and C.U. Grosse
Publisher: RILEM Publications SARL
Publication year: 2005
Pages: 1 - 11
Total Pages: 11
Nb references: 10
Abstract: Concrete is a composite material consisting of five components: cement, water, aggre-gates, additions and admixtures. Cement is here taken as a synonym for the binder which can consist of the main component which is the portland cement klinker and of the sec-ondary products such as fly ash, ground granulated furnace slag, puzzolanas, silica fume, burnt shale and others. These secondary products can also be used in concrete as addi-tions when mixing the concrete. The aggregates are either natural stone, crushed or rounded, or man made products like slag or expanded lightweight aggregate. The admix-tures, finally, are mostly chemical products. They are added to the mix in order to influ-ence either the fresh state like plasticizer, superplasticizer, accelerator, retarder and stabi-lizer, or to improve the hardened state like the air entraining agent.
Concrete is mixed in the fresh state. The fresh state is a suspension with high viscosity. The conventional way to compact the concrete such that all random air bubbles can escape and that a homogeneous material is created is to vibrate the concrete. Due to vibrations the visco-plastic (thixotropic) material starts to flow and fills a form com-pletely embedding all reinforcing steel tightly. Modern concrete technology allows to make a self-compacting concrete which flows without any vibration. Physically speaking fresh concrete can be modelled as a Bingham fluid with a yield limit (or strength) and a viscosity.
This brings us to the aim of the RILEM TC 185-ATC (Advanced testing of cement based materials during setting and hardening). The aim of the technical committee is to collect the knowledge on non-destructive measuring techniques and to write a state-of-the-art report. Furtheron, round robin tests are planned which use the same test material at various places with different testing devices. This should allow a reliable correlation of the test results. The results of the TC´s activities are written down in the following chapters.
Online publication: 2006-09-22
Publication type : full_text
Public price (Euros): 0.00