Comparative study of early age cracking in HPC and NPC structures

Title: Comparative study of early age cracking in HPC and NPC structures
Author(s): A. Nagy
Paper category : conference
Book title: International RILEM Conference on Early Age Cracking in Cementitious Systems
Editor(s): K. Kovler and A. Bentur
Print-ISBN: 2-912143-29-2
e-ISBN: 2351580362
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 319 - 326
Total Pages: 8
Nb references: 6
Language: English

Abstract: A comparative study of HPC (High Performance Concrete) and NPC (Normal Performance Concrete) structures is made with regard to thermal cracking at early ages. Two reference walls with approximately the same bearing capacity are studied by means of FEM-simulations. Special attention is paid to parameters dominating cracking at early ages: the difference between placing temperature and adjoining concrete, cement type, and the ambient temperature variation.

It is concluded that the HPC wall is more sensitive to early age cracking and needs more differentiated crack control criterions than the NPC structure. The most effective crack control criterion is the temperature difference between placing temperature and adjoining concrete. Halving the temperature difference leads to a crack risk reduction of about 35%. The effect of autogenous shrinkage can be reduced to half by using low heat cement in combination with low difference between placing temperature and adjoining concrete. The HPC structure seems to be less affected by early form removal and the influence of wind. The practical benefit with a realistic simulation of the ambient temperature is that a general reduction of crack risk level takes place in most of the investigated cases.

Online publication: 2010-06-02
Publication type : full_text
Public price (Euros): 0.00