Over the two years project programme, six months were available for the work on chemical soil stabilisers, review of case studies and fibre reinforced soils. This work was split into three parts and report 7 details the third part of this element of the research that concentrated on the use of fibres for stabilising soils. This included both synthetic and natural fibres.
Laboratory work was conducted on polypropylene fibres and both laboratory and field trials were conducted sisal fibre (natural fibre). Much of the work on using fibres was conducted in Uganda by the Ministry of Transport, Communication and Public Works. A field trial comprising construction of a road section was conducted on fibre reinforced laterite in Uganda.
The effect of three lengths (6, 12 and 18 mm) of polypropylene fibres at concentrations ranging from zero to 0.6% on the density, compressive strength and CBR of Oxford clay were investigated. The effect on density, UCS and CBR of 12 mm long sisal fibres ranging in concentrations from zero to 0.6% was investigated for laterite soil stabilised with lime and
cement. The latter were at both 4 and 6% concentrations. Four, ten metre long section of road were constructed with reworked laterite, lime stabilised laterite and fibre reinforced and lime stabilised laterite. In the trials 12 mm long (nominal length) sisal fibres at 0.2 % concentration, and 4% lime were used.
The fibre reinforced cement stabilised study was a pilot investigation to assess suitability of this material for pothole repair. The effect of fibres on dry density, UCS and CBR were measured. A field trial was conducted in Uganda on repairing potholes with fibre reinforced cement stabilised laterite.