Focke, Walter WilhelmGermishuizen, Willem AndreasVisser, Alex T.2014-05-222014-05-222003Focke, WW, Germishuizen, WA & Visser, AT 2003, 'A laboratory optimisation of a urea-formaldehyde soil stabiliser', South African Journal of Chemical Engineering, vol. 15, no. 1, pp. 1-16.1026-9185http://hdl.handle.net/2263/39872The Indirect Tensile Strength (ITS) was used to characterise the soil stabilising properties of a urea-formaldehyde (UF) resin. The test soil was brown shale gravel. Synergistic strength improvements were obtained when combining the resin with anionic bitumen emulsion and dosing both at 2%. Performance levelled off above these concentrations. For full strength development, the soil moisture content must be reduced to below 3%. Optimum indirect tensile strength is obtained at formaldehyde to urea molar ratio of 2:1. Soil strength increases as the reaction pH is lowered but the need for adequate application times restricts it to pH > 4,5. The experimental results also suggest that the presence of appropriate organic matter is critical for effective soil stabilisation with UF resin.Die Indirekte Treksterkte (ITS) is gebruik om die grondstabilisasie-eienskappe van ‘n urea-formaldehied hars (UF) te kwantifiseer. Die toetsgrond was ‘n bruin skaliegruis. Kombinasie van die hars met ‘n anioniese bitumen emulsie toon sinergistiese sterkteverbetering wanneer beide doseer word op die 2% vlak. Werkverrigting plat af bokant hierdie konsentrasies. Vir volle sterkteontwikkeling moet die grondvogtigheid verlaag word tot onder 3%. Optimale indirekte treksterktes word behaal met ‘n formaldehied-tot-urea molverhouding van 2:1. Grondsterkte neem ook toe soos die reaksie pH verlaag word maar vir pH < 4,5 word die beskikbare aanwendingstyd ontoereikend. Die eksperimentele resultate dui ook daarop dat die teenwoordigheid van ‘n geskikte organiese fraksie in die grond krities is vir effektiewe stabilisasie met UF hars.enSouth African Institute of Chemical EngineersSoilStabilisationUrea formaldehyde resinStrengthGrondStabilisasieUrea-formaldehied harsSterkteArticle