Krapow Posted December 19, 2019 Posted December 19, 2019 For sand, from China? Knew about the dams, but didn't know about this. https://www.bbc.co.uk/news/business-50629100 1 2
Lemondropkid Posted December 19, 2019 Posted December 19, 2019 Interesting article- no surprise to see Cambodia get a mention. They seem to have allowed Chinese investment regardless of its impact on it's own citizens , let alone the environment. Amazing stat- "China consumed more sand between 2011 and 2013 than the US did in all of the 20th Century, as it urbanised its rural areas. "
Toy Boy Posted December 20, 2019 Posted December 20, 2019 A mate is doing a long bike trip up in Isaan and he's just been driving along the Mekong. He posted some pics on FB showing that the river is a lovely shade of blue now, he's never seen it like that, it's normally a brownish colour. He's speculating that the new dams upstream are holding back the sediment that usually gives it the brown colour. 3 2
Krapow Posted December 20, 2019 Author Posted December 20, 2019 Going up to Chiang Rai and the Golden Triangle in June. Looking forward to seeing the Mekong.
Freee!! Posted December 20, 2019 Posted December 20, 2019 That sand should be taken from the sea bottom. 1
Thai Spice Posted December 20, 2019 Posted December 20, 2019 2 hours ago, Freee!! said: That sand should be taken from the sea bottom. Sea sand contains salt. Salt is corrosive for the steel reinforcement in the concrete structure. Hence sea sand need to be "washed". This plus the cost os sea dredging probably makes it less economicaly interesting. It is a vast subject, type of sand (granulosity) and purpose (glass making or concrete) , check out Google. An example : "Sea sand can be used in concrete when regular sand is not available. The main worry is about the durability related properties as the sea sand has large amount of salts adhered on the its surface. Just water washing may not remove all deleterious materials firmly adhered on to the surface. Pressure washing and chemical washing remove all such materials. Sea sand is some what fine and smooth. It will have influence on the mechanical properties of concrete. For producing low to medium strength concrete, there may not be significant difference in the properties. For special concretes, the river sand should be characterized before use. Chlorine induced corrosion is a main problem. Sea sand has no serious problem in plain and non structural concrete applications." 1
grayray Posted December 21, 2019 Posted December 21, 2019 On 12/20/2019 at 3:37 AM, Krapow said: For sand, from China? Knew about the dams, but didn't know about this. https://www.bbc.co.uk/news/business-50629100 get young Greta to sail up the Mekong and lecture the Chinnesse,that will have the climate mob talking. iam sure the leaders in China will be shaking in their boots regards grayray 1 1 1
Krapow Posted December 21, 2019 Author Posted December 21, 2019 Yea, they can't use the desert sand either, too coarse.
KWA Posted December 22, 2019 Posted December 22, 2019 13 hours ago, Krapow said: Yea, they can't use the desert sand either, too coarse. Other way round - it's too fine - but it looks like science is working a way round that, so the problem could reduce if they can make it cost effective. 2
Krapow Posted December 22, 2019 Author Posted December 22, 2019 6 hours ago, KWA said: Other way round - it's too fine - but it looks like science is working a way round that, so the problem could reduce if they can make it cost effective. Oh well, i'd a 50% chance of getting it right 😆
tommy dee Posted December 22, 2019 Posted December 22, 2019 the mekong is s low that the barges cant float in places. chinky dams have done it in good and proper and with the drought expected to start asuia wide in a few months time, it could end up as a trickle
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