RISA | Tips & Tricks

RISA | Updates to ACI Concrete Code in ADAPT-Builder

Written by RISA | Jan 01, 2021
 

ADAPT-Builder v20 has been updated to ensure that users can take advantage of designs conforming to the latest building code standards. The 2020 version includes applicable code provisions from ACI318-19: Building Code Requirements for Structural Concrete. Provisions found in the latest design standard that have been included in ADAPT-Builder include:

  • Reinforcement strain limit has been revised for all criteria and system types (beam, one-way and two-way slabs for RC and PT mode). (ACI 318-19, 7.3.3.1)

  • Minimum flexural reinforcement for non-prestressed, reinforced one- and two-way slabs shall meet a minimum area of flexural reinforcement of 0.0018Ag. (ACI 318-19, 7.6.1.1)

  • For two-way non-prestressed, reinforced concrete slabs the equation for modulus of rupture is modified for fy exceeding 80,000 psi. This change applies to cracked deflection calculations in the program where fr is used to calculate cracking moments, Mcr. (ACI 318-19, 8.3.1.1)

  • Minimum extensions for deformed reinforcement. Bar curtailment in Buildersum was adjusted for compliance. (ACI 318-19, Figure 8.7.4.1.3)

  • The reinforcement strain limit for beams. (ACI 318-19, 9.3.3.1)

  • For the calculation of the minimum flexural reinforcement amount for beams with fy exceeding 80,000 psi, the value of fy shall be limited to a maximum of 80,000 psi. (ACI 318-19, 9.6.1.2)

  • One-way shear strength provisions for non-prestressed members in relation with the calculation of Vc for non-prestressed members have been modified per Table 22.5.5.1 (see below) and sections 22.5.5.1.1 through 22.5.5.1.3. ACI 318-19, 22.5.5.1 and 22.5.5.1.3

  • The requirements for Av,min for non-prestressed and prestressed beams are modified. (ACI318-19, 9.6.3.1 and 9.6.3)

  • The calculation of Vc for prestressed members has been modified for those members where the full effective prestress force has been transferred to concrete. (ACI318-19, 22.5.6.2)

  • For two-way shear of slabs, a new size effect factor, λ is introduced in the allowable concrete shear stress, Vc, without shear reinforcement. (ACI 318-19, Table 22.6.5.2)

  • For the check of cracked deflections at service level conditions, the effective moment of inertia, Ie equations have been revised for non-prestressed members. For non-prestressed members, unless obtained by a more comprehensive analysis, effective moment of inertia (Ie) shall be calculated in accordance with Table 24.2.3.5. (ACI 318-19, 24.2.3.5)

  • In ACI 318-19, R24.2.3.5, the effective moment of inertia approximation developed by Bischoff and Scanlon is adopted and Branson equation (ACI 318-14, Eq. 24.2.3.5a) is removed from ACI 318-19. For prestressed members, the provisions found in ACI318-14 continue to apply and are described in ACI318-19, 24.2.3.9.