*xm portland (pc) 
 -la chat ket djh vo co ben nc la 1 sp nhan tao dc nghjen mjn tu  CLK XM PORTLAND voj 1 luog thach cao can thjet .T/p cua xm bao gom:
  +clinker xm:95-96%
  +Thach cao:4-5%
  +phu gja cog nge(neu co):nho hon hoac =1%
-chat luog of xm portland fu thuoc vao chat luog of clk va do nghjen mjn of xm (luog sot sang 0,09<,=12%,ty djen 2700-3200cm2/g).
-dug de xd cac cog trjh tren can va duoj nc va dc sd lam xm nen de fa tron voj dag bot mjn of cac khoag khac nhau de tao ra cac loaj xm portland hon hop co t/c ki thuat uu vjet # nhau de dug trog cac cog trjh xd doj hoj nhug cong nang sd # nhau.