Modification of traditional Chinese ginger nut and its mechanical behavior

The ginger nut has been used as building materials in Dadiwan site in Qin'an County, Gansu Province, China, and it was confirmed as the earliest lightweight concrete in China. However, the ginger nut is not a proper construction material because it does not contain cementitious components. In this paper, original ginger nut were calcined under different temperatures and the properties of the resultant modified ginger nut were analyzed. 1100 °C was chosen as optimal calcination temperature according to CaO, β-CaSiO3 and Ca2Al2SiO7 content. Based on mortar workability and strength as result of curing time, 0.33 was selected as the optimal water binder ratio of the ginger nut mortar. The results of the mechanical tests revealed that the mortar exhibited ductile behavior, and it is possibly due to the special structure between aggregates and hydration or carbonation products. Finally, several tests carried out to determine weathering resistance abilities of the ginger nut mortar showed that they will probably serve as restoration material for stone or soil relics.