Posted on 05/29/2010 6:02:14 PM PDT by decimon
Note to journalists: Please credit the journal or the American Chemical Society as the source
WASHINGTON, May 29, 2010 Scientists have discovered the secret behind an ancient Chinese super-strong mortar made from sticky rice, the delicious "sweet rice" that is a modern mainstay in Asian dishes. They also concluded that the mortar ― a paste used to bind and fill gaps between bricks, stone blocks and other construction materials ― remains the best available material for restoring ancient buildings. Their article appears in the American Chemical Society (ACS) monthly journal, Accounts of Chemical Research.
Bingjian Zhang, Ph.D., and colleagues note that construction workers in ancient China developed sticky rice mortar about 1,500 years ago by mixing sticky rice soup with the standard mortar ingredient. That ingredient is slaked lime, limestone that has been calcined, or heated to a high temperature, and then exposed to water. Sticky rice mortar probably was the world's first composite mortar, made with both organic and inorganic materials.
The mortar was stronger and more resistant to water than pure lime mortar, and what Zhang termed one of the greatest technological innovations of the time. Builders used the material to construct important buildings like tombs, pagodas, and city walls, some of which still exist today. Some of the structures were strong enough to shrug off the effects of modern bulldozers and powerful earthquakes.
Their research identified amylopectin, a type of polysaccharide, or complex carbohydrate, found in rice and other starchy foods, as the "secret ingredient" that appears to be responsible for the mortar's legendary strength.
"Analytical study shows that the ancient masonry mortar is a kind of special organic-inorganic composite material," the scientists explained. "The inorganic component is calcium carbonate, and the organic component is amylopectin, which comes from the sticky rice soup added to the mortar. Moreover, we found that amylopectin in the mortar acted as an inhibitor: The growth of the calcium carbonate crystal was controlled, and a compact microstructure was produced, which should be the cause of the good performance of this kind of organic-organic mortar."
To determine whether sticky rice can aid in building repair, the scientists prepared lime mortars with varying amounts of sticky rice and tested their performance compared to traditional lime mortar. "The test results of the modeling mortars shows 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," the article notes.
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Note to journalists: Please credit the journal or the American Chemical Society as the source
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 161,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
DOWNLOAD FULL TEXT ARTICLE: http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/ar9001944 ACS' Accounts of Chemical Research "Study of Sticky Rice-Lime Mortar Technology for the Restoration of Historical Masonry Construction"
Side of rice ping.
Mortar, not a “Mortar”. Strangely I’m disappointed.
And you don’t have to order out for lunch!
"someone shudda slip a few rice balls in with Odumbo's tarballs, that wudda had him mmmmming and ahhhhing"
This does not surprise me in the least. I bet grits would make a good glue, too.
Yeah, I was thinking of a mortar that shot sticky rice too.
“It’s the cereal that’s shot from guns!”
The Kung Pow Gun?
A lot of folks involved in the restoration of brick homes here in the USA mistakenly use cement rather then mortar or re-pointing brick homes.
The cement is harder then the brick. During temperature changes the brick with expand at different rates then the brick. Because it is stronger then the brick, it will actually break the bricks hard face off.
I can see how cooked Rice would have not break the material it was used to mortar together.
Not news to any cook who forgot to rinse out the rice pot till the following morning.
A lifetime of constipation can leave you with a permanent squint.
You mean the spouse of anyone who fails to rinse the rice pot.
I do most of the cooking in the house but when my wife has to make the starch before dinner she usually fails to soak the pot afterwords.
Had a little place on Caobao Lu try to serve me that sticky rice mortar... Me and the waitress had a little talk and got it sorted out, though...
I’m so old I thought that Calgon Water Softener was the ancient Chinese secret.
Several trivia bits.
First of all, in the US, we know sticky rice as “short grain rice”, which is uncommon, compared to the “long grain rice” we typically eat. Short grain rice is favored by the better Oriental restaurants because of its sticky texture and moistness compared to long grain.
Second, the purpose of mortar is primarily to provide as flat a surface as possible for the stone, block or brick. This distributes the weight, and any bulge or gap in the mortar that causes uneven distribution acts as a force multiplier to damage the stone, block or brick.
Third, mortar determines the strength of the wall or building. The better the mortar, the longer it will last, and the easier ti will be to be repaired.
Some Rice Krispie treats can get pretty hard if left out too long. The sticky rice used in Chinese cooking gets its stickiness from the glutens in the soft rice as opposed to marshmallows in the treats. Often the rice is used to coat dim sum dumplings (in lieu of the flour-based buns or won-ton sheets).
Although the species of rice plants may be different, quite a few Italian dishes call for rice with a soft, sricky consistency. Maybe Marco Polo and crew kept themselves alive by hanging around construction sites in China.
The most common mortars used in construction are types M, S and N. This ancient mortar must have been type R (rice).
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