Title:
Natural Rubber Latex as Admixture for Polymer Concrete
Author(s):
My Linh Vo and Johann Plank
Publication:
Symposium Paper
Volume:
330
Issue:
Appears on pages(s):
31-42
Keywords:
natural rubber latex; ethylene vinylacetate; film forming polymer; latex; retardation; cement mortar; mortar tests; tensile strength
DOI:
10.14359/51711238
Date:
9/26/2018
Abstract:
The applicability of Natural Rubber Latex (NRL) as film forming agent was tested in mortar.
Two NRL samples, a commercial concentrated and a laboratory-treated, deproteinized one, were compared with a commercial synthetic ethylene-vinylacetate (EVA) copolymer regarding their particle size distribution, surface charge and minimum film forming temperature (MFFT). Additionally, a potential retarding effect of the dispersions was investigated by heat flow calorimetric measurements. Cement mortars holding 2 percent by mass of the dispersions were tested for their strength development after 1, 3, 7 and 28 days.
NRL exhibits an average particle size of 350 nm, possesses a highly anionic charge and possesses a MFFT of ~1 °C (34 °F). Heat flow measurements show that the non-treated NRL retards cement hydration. Mortar tests revealed that both NRL samples showed slightly higher strength values than the industrial EVA latex. However, the NRL latexes require addition of a PCE superplasticizer to achieve workability and strong defoamers.