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## Research on application of waste PET for concrete modification

### Daniel Wiliński

#### Abstract

The diploma thesis entitled "Research on application of waste PET for concrete modification" presents the properties of cement-based composites containing recycled PET fibers. These fibers were obtained by simple mechanical cutting of plastic bottles. Waste PET can be reuse as partial and complete substitutes of an aggregate in concrete composition or as a concrete reinforcement. However, the main drawback of such approaches is alkaline hydrolysis of the poly(ethylene terephthalate) under high alkali concentration (pH = 12-13.5) characteristic for concrete mortar environment. The first part contains the overview of the literature. It comprises the characteristics of polymer concretes, fiber-reinforced concrete. There are also examples of the use of waste PET for concrete modification and the description of polymeric waste problem and degradation of PET fibers by alkaline hydrolysis. In the second part the results of research are presented. The chemical resistance of the PET against hydrolysis was improved by dip coating method in a solution of EVA copolymer. However, but adhesion of protective layer to slippery PET surface was not satisfactory. To improve adhesion the protective layer PET surface was modified by oxidation, etching, hydrolysis, surface roughening or plasma modification. The lowest endurance decrease of fibers in alkaline environment was received by oxidation with the use of hydrogen peroxide. The results were highly influenced by fiber characteristics and content in the fresh concrete mixture (i.e. concrete with 0,11% vol. additive of fibers from 5 to 7 cm long and width of 2 mm after 28 days exhibited compressive strength of 35,23 ± 0,50 MPa, whereas the concrete without fibers: 34,56 ± 0,50 MPa). Decreases the concrete slump as a result of addition of fibers might be eliminated by addition of superplasticizer. Precast concrete units containing fibers fulfilled criteria, that will decide about building development in XXI century. Those fibers might be produced from waste such as PET. Their price might be only a fraction of price of commercial reinforcing fibers. It is important that produced PET should not lose their characteristics in time. Therefore, there should be a protection layer on them. Effectiveness of the use of copolymer EVA as protection layer against strong alkali solutions has been proven.
Record ID
WUTd6778b4b94d74b3580dfe62603f6324f
Diploma type
Master of Science
Author
Daniel Wiliński Daniel Wiliński,, Undefined Affiliation
Title in Polish
Supervisor
Gabriel Rokicki (FC/CPCT) Gabriel Rokicki,, Chair Of Polymer Chemistry And Technology (FC/CPCT)Faculty of Chemistry (FC)
Certifying unit
Faculty of Chemistry (FC)
Affiliation unit
Chair Of Polymer Chemistry And Technology (FC/CPCT)
Study subject / specialization
, Technologia Chemiczna
Language
(pl) Polish
Status
Finished
Defense Date
26-07-2012
Issue date (year)
2012
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
urn:pw-repo:WUTd6778b4b94d74b3580dfe62603f6324f