Secoin concrete blocks have been tested at specialized laboratories and have been proved to be in conformity with Vietnamese standard (TCVN 6477:1999 for concrete block) as well as European and Internaional standards (such as JIS-A 5406:1994 - Japanese Standards and AS 2733:1984 - Australian Standard). Secoin concrete blocks are being producsd under the International quality management ISO 9001:2000. ALLOWED EXTERIOR DEFECTS Criteria Achieved Bending of tile surface (mm), not exceeding 3 Number of edge chips (*), not exceeding 4 Number of cracks with length not over 20mm, not exceeding 1   (*) For hollow block Depth of 5-10mm, length of 10-15mm SIZE - WEIGHT Allowed tolerance of weight: ±10% Allowed dimension tolerance of hollow block: Width and length: ±2mm; height: ±3mm   PHYSICAL PROPERTIES Level of strength Compressive strength, kg/cm2, not less than Water absorption, %, not exceeding M35 35 - M50 50 - M75 75 10 M100 100 10 M150 150 8 M200 200 8 Technical specification   Model Dimension (mm) Coverage (Pcs/m2) Weight (kg/pc) Note SHB1 - 135 135 x 100 x 190 35.5 3.5 For 100, 140 thick wall SHB3 - 80 390 x 80 x 190 13.5 8.0 For 80 thick wall SHB3 - 100 390 x 100 x 190 13.5 10.5 For 100 thick wall SHB3 - 150 390 x 150 x 190 13.5 14.5 For 150 thick wall SHB3 - 165 390 x 165 x 190 13.5 17.0 For 165 thick wall SHB3 - 190 390 x 190 x 190 13.5 18.5 For 190 thick wall   Model Dimension (mm) Coverage (Pcs/m2) Weight (kg/pc) Note SHB2 - 100 390 x 100 x 190 13.5 9.0 For 100 thick wall SHb2 - 150 390 x 150 x 190 13.5 12.0 For 150 thick wall SHB2 - 190 390 x 190 x 190 13.5 14.0 For 190 thick wall SBH2 - 100/2 400 x 100 x 200 12.5 10.0 For 100 thick wall SBH2 - 200/2 400 x 200 x 200 12.5 16.5 For 200 thick wall