A new study by the American Chemical Society suggests that sticky rice may have been the secret ingredient in the powerful mortar used by the ancient Chinese.
“Analytical study shows that the ancient masonry mortar is a kind of special organic-inorganic composite material,” said Professor Bingjian Zhang of China’s Zhejiang University. “The inorganic component is calcium carbonate, and the organic component is amylopectin, which comes from the sticky rice soup added to the mortar.”
Zhang worked with a team to test the hypothesis by mixing lime mortars with various amounts of sticky rice and compared the results with traditional lime mortar.
The American Chemical Society reported in their monthly journal that “the test results of the modeling mortars show that sticky rice-lime mortar has more stable physical properties, has greater mechanical strength, and is more compatible, which make it a suitable restoration mortar for ancient masonry.”