Mechanical properties of concrete with SAP part I: Development of compressive strength

Title: Mechanical properties of concrete with SAP part I: Development of compressive strength
Author(s): M.T. Hasholt, M.H.S. Jespersen, O.M. Jensen
Paper category : conference
Book title: International RILEM Conference on Use of Superabsorbent Polymers and Other New Additives in Concrete
Editor(s): O.M. Jensen, M.T. Hasholt and S. Laustsen
Print-ISBN: 978-2-35158-104-9
e-ISBN: 978-2-35158-105-6
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 117 - 126
Total Pages: 10
Nb references: 11
Language: English

Abstract: The development of mechanical properties has been studied in a test program comprising 15 different concrete mixes with 3 different w/c ratios and different additions of superabsorbent polymers (SAP). The degree of hydration is followed for 15 corresponding paste mixes. This paper concerns compressive strength. It shows that results agree well with a model based on the following:
1. Concrete compressive strength is proportional to compressive strength of the paste phase
2. Paste strength depends on gel space ratio, as suggested by Powers
3. The influence of air voids created by SAP on compressive strength can be accounted for in the same way as when taking the air content into account in Bolomeys formula.
The implication of the model is that at low w/c ratios (w/c < 0.40) and moderate SAP additions, SAP increases the compressive strength at later ages (from 3 days after casting and onwards), because SAP increases the degree of hydration and therefore also the gel space ratio of the paste. However, at high w/c ratios (w/c > 0.45) and addition of large amounts of SAP, this effect cannot counterbalance the strength reducing effect of increased void volume. In these cases, SAP addition reduces the compressive strength.

Online publication: 2010-10-04
Publication type : full_text
Public price (Euros): 0.00