the fiber addition also reduces the incidence of segregation of the larger aggregate particles while curing the use of about 1 inch long polypropylene microfibers in the mix is preferred when the product will be installed in lifts thicker than about u00bd inch to increase the flexural strength of the layer and also reduce its ability to crack under flexure over the long term commercially available micro fiber materials to meet the foregoing requirements include those from durafiber inc nashville tenn or equivalent this invention uses a pozzolanic filler in the dry blend to improve the workability of the mix reduce the shrinkage of the cured material and improve the long term strength development of the cured material this invention uses a type c or type f fly ash filler to improve the resistance of the mix to the development of alkali silica reactivity asr in areas where the local type 2 aggregate or c144 aggregate contain high silica components commercially available fly ash materials which meet this requirement include boral fly ash available from boral material technologies inc san antonio tex or an equivalent this invention uses a dry redispersible polymer so as to improve the quality control during the mixing of the product on site a dry polymer will allow the blended mixture to be delivered to the site and simply require the introduction of water only which simplifies the mixing and placing operation on site the redispersible polymer also has a defoaming and self leveling action to assist with the reduction of air during the mixing process that is common in polymer modified mortars the reduction of air improves the impermeability of the surface mix and increases the abrasion resistance of the.