* Shanghai steel rebar prices up 1.3 pct this week
* Infrastructure projects to drive steel demand in China
SINGAPORE, Sept 21 (Reuters) - China's construction steel rebar prices slid for a second session on Friday, but the market is poised to finish the week on a positive note supported by the country's plans to increase infrastructure spending.
The most-active rebar on the Shanghai Futures Exchange SRBcv1 slid 0.3 percent to 4,132 yuan ($603.85) a tonne by 0159 GMT. For the week, the market is up 1.3 percent.
"Steel futures have been strong off the back of ongoing curbs to steel capacity amid strong demand," ANZ said in a report. "However, this enthusiasm has been tempered in recent days by reports that the curbs may not be as extensive as last year."
China's steel demand will remain firm despite the country's escalating trade war with the United States, and any efforts by Washington to "sabotage" the Chinese economy will not succeed, the head of China's steel association said. push to expand subway networks in some of China's biggest cities are helping brighten the outlook for the nation's mammoth steel sector.
The National Development and Reform Commission, the top state planner in the country, has said China would ramp up investment in infrastructure.
Iron ore on the Dalian Commodity Exchange DCIOcv1 was unchanged at 502.5 yuan a tonne. Coke DCJcv1 gave up 0.8 percent to 1,275.5 yuan a tonne and coking coal DJMcv1 added 0.3 percent to 2,328 yuan a tonne.
China's iron ore demand is expected to stay flat, said an official from Baoshan Iron & Steel Co, the country's biggest listed steelmaker, as Beijing's stricter environmental rules boost the use of scrap steel.
Mining giant Vale is looking at expanding its flagship iron ore project in Brazil, a company official said, hoping to cash in on a growing appetite for higher-grade varieties of the commodity in China.
China has ramped up buying of higher-quality, less polluting grades of iron ore as it battles to clear its notoriously smoggy skies.
($1 = 6.8428 Chinese yuan)