Title:
Concrete Q&A: Formwork Removal Times and Clear Spacing for Parallel Reinforcement
Author(s):
Publication:
Concrete International
Volume:
42
Issue:
8
Appears on pages(s):
63-34
Keywords:
DOI:
10.14359/51728110
Date:
8/1/2020
Abstract:
Which ACI documents include information regarding the timing for removing forms?
Section 25.4.2.3 of ACI 318-191 refers to Table 25.4.2.3 for calculation of development length for deformed bars. Is the indicated clear spacing in Table 25.4.2.3 measured between the lapped bars or between adjacent splices? If we allow noncontact splices and require that they meet the requirements of Section 25.5.1.3, with center-to-center spacing of the lapped bars being no more than lap-length/5 or 6 in., is the lap length the same as it would be for a contact splice?
Related References:
1. ACI Committee 347, “Guide to Formwork for Concrete (ACI 347R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 36 pp.
2. ACI Committee E703, “The Contractor’s Guide to Quality Concrete Construction (MNL-5(19)),” ACI/ASCC Manual, 4th edition, American Concrete Institute, Farmington Hills, MI, 2018, 262 pp.
3. ACI Committee 301, “Specifications for Structural Concrete (ACI 301-16),” American Concrete Institute, Farmington Hills, MI, 2016, 64 pp.
4. ACI Committee 347, “Guide for Shoring/Reshoring of Concrete Multistory Buildings (ACI 347.2R-17),” American Concrete Institute, Farmington Hills, MI, 2017, 28 pp.
5. ASTM C1074-11, “Standard Practice for Estimating Concrete Strength by the Maturity Method,” ASTM International, West Conshohocken, PA, 2011, 10 pp.
6. Lee, C.H., and Hover, K.C., “Maturity-Based Strength Predictions,” Concrete International, V. 38, No. 9, Sept. 2016, pp. 48-55.
7. Johnston, D.W., “Formwork for Concrete,” SP-4, 8th edition, American Concrete Institute, Farmington Hills, MI, 2014, 512 pp.