Wind tunnel experimental study on sand-fixing effect of fly ash and polyacrylamide

Searching for an effective and economical sand fixation measure has important significance in wind erosion control. Wind tunnel experiments were conducted to study the sand-fixing effect of fly ash at three different application rates (10%, 20% and 30%) and the intensifying action of polyacrylamide (PAM) at two different application rates (0.05% and 0.1%) on it on the basis of the optimum fly ash application rate. The results indicated that fly ash increased the threshold wind speed of the treated soil significantly, which was further increased by PAM slightly. The soil treated with 20% fly ash could most effectively withstand pure wind and sand-carrying wind with a wind speed of 8 m/s for 10 min respectively. Moderate wind erosion occurred after exposure to pure wind and sand-carrying wind with a wind speed of 14 m/s for 10 min respectively, and there was a decline in the wind erosion rate with the increase of fly ash application rate. The soil treated with 20% fly ash and PAM could effectively withstand sand-carrying wind with a wind speed of 14 m/s for 30 min. 20% fly ash application rate and 0.05% PAM application rate were recommended to realize effective and economical wind erosion protection.