Civil Engineering Reference
In-Depth Information
16
Concrete with polymers
M. Frigione, University of Salento, italy
DOI
: 10.1533/9780857098993.3.386
Abstract
: This chapter describes the use of different polymers that can be
added to fresh or hardened hydraulic cement, or used to replace the cement.
The introduction of polymers can modify the characteristics and properties
of concrete, and protect or repair concrete elements.
Key words
: polymer admixtures, superplasticizers, polymer-modified
concrete (PMC) polymer-impregnated concrete (PiC), polymer concrete,
(PC), coatings, adhesives.
16.1 Introduction
in Western europe polymers represent only 1% in weight of all construction
materials (2007 data), but in financial turnover polymers represent more
than 10% of the construction industry. The available data indicates a steady
increase in the use of polymers in construction (euPC 2006). The amount
of polymers used in concrete-polymer composites is only a minor part of
the total used for concrete modification (total consumption of 486 000 tons
in 2000), which also includes water-reducing agents (121 500 tons of super-
plasticizer in eU in 1998). The use of polymer admixtures in concrete will
further increase. new environmental regulations and higher-quality demands
will require admixtures for nearly all ready-mixed concretes. This evolution
opens a yearly market of several million tons of admixtures (Van gemert
and Knapen 2010).
Polymers used in concrete have been developed within the past 60-70
years. Four main kinds of polymers can be distinguished as increasing
function of the polymer content with respect to cement:
∑
in Portland cement concrete (PCC) the properties and performance of
concrete are largely determined by the properties of the hydraulic cement
paste that is the active constituent. Polymer admixtures are ingredients
that, added in small quantities (usually below 3% wt) to the concrete
batch, immediately before or during mixing, interact in the hydrated-
cementitious system by physical, chemical and physical-chemical action
modifying one or more properties allowing wider concrete applications,
conferring certain beneficial effects to concrete, including enhanced
durability, improved workability, increasing strengths.
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