(Part-A) স্ট্রাকচার ডিজাইনের মানদণ্ড এবং ন্যূনতম প্রয়োজনীয়তা। (STRUCTURAL DESIGN CRITERIA & MINIMUM REQUIREMENTS)

                   

                 STRUCTURAL DESIGN CRITERIA &  MINIMUM REQUIREMENTS 

         1.GENERAL

A.              A. Ultimate Strength Design (USD) method is used as per Bangladesh National                       Building Code (BNBC) 1993, UBC 1997 & ACI 318-05.

B.              B. Follow BNBC 1993 for specifications/ structural requirements not mentioned in the             drawings or in this note sheet.

C.              C. Any details not shown in the drawing should be done according to ACI Detailing                 Manual – 1994

             2. CONCRETE

        TYPE: Concrete Compressive Design Strength considered as follows:

                    For Concrete, f'c = minimum 20 Mpa for All Concrete.

     MINIMUM CYLINDER STRENGTH : Based on standard cylinders as per standard                    practice of Code ACI/ BNBC/ ASTM

                     A. 28 Days strength = 20 Mpa

                     B. 7 Days Strength = 65% of the 28 days strength

     CURING OF R.C.C WORK :

     Curing Time minimum 28 days

      Method of Curing:

     ·       Horizontal surface - by ponding of Water

Horizontal surface - by ponding of Water

·       Other surfaces - by wrapping moist jute fabric and sprinkling water by hose pipe frequently.

Vertical surface - by wrapping moist jute fabric 

    3.CEMENT

            Cement Conforming to BDS EN 197-1:2003 CEM-1 52.5 N /ASTM-C 150 Type-I

    4.CONCRETE AGGREGATE

       FINE AGGREGATES: Best quality Sylhet sand or coarse sand of equivalent F.M. 2.50           (Min.)

Sylhet sand F.M. 2.50

COARSE AGGREGATES : 20mm  Down well graded Stone chips confirming to ASTM C-33 to be used as coarse aggregate in all R.C.C. work except railing, drop wall & fins for which 12mm down graded Stone chips to be used.

20mm  Down well graded Stone chips 

5.WATER

            Potable water to be used in concrete mix.