Detachment was one of the most critical problems affecting the Cave 85 murals at the Mogao Grottoes.According to the actual characteristics of the detached murals,81 grout formulations were tested.A number of materials with potentially useful properties were identified and assessed,and tested both in the laboratory and in detachment simulation experiments.A mixture of denbantu(an earthen sediment of the local river),pumice,glass microspheres,and water was eventually selected for the optimized recipe.Among the most advantageous performance characteristics of the mixture were low density,minimal shrinkage,moderate and adjustable cohesive strength,and compatible water vapour permeability.It also had excellent working properties,such as good fluidity.The in-situ experiments demonstrated that the mixture was an excellent grouting material for the detachment problem in Cave 85 at Mogao Grottoes.
