Title: Proposed Revisions to ACI 307-69: Specification for the Design and Construction of Reinforced Concrete Chimneys
Author(s): ACI Committee 307
Publication: Journal Proceedings
Appears on pages(s): 421-428
Keywords: chimneys;compressive strength;concrete construction;dead loads;earthquake resistant construction;formwork (construction);foundations;high temperature;linings; loads (forces);moments;openings;quality control;reinforced concrete;reinforcing steel.
This report lists proposed rvisions to the current standard. If approved, they will be incorporated into the standard and resulting document will supersede ACI 307-69. The specification gives material, construction, and design requiremens for reinforced concrete chimneys. The report sets forth reccommended loadings for the design of reinforced concrete chimneys and reccommended methods for determining the stresses in the concrete resulting from these loadings. Charts containing curves to aid in the rapid solution of the specified formula are included. While the method of analysis applies primarily to chimneys, it can be used for other hollow circular cross sections, with or without openings, where the shell thickness is small inproportion to the diameter. Formulas are recommended for determining the temperature gradient through the concrete resulting from the difference in temperature of the gases inside the chimney and surrounding atmosphere, together with methods for determining the stresses in the concrete and reinforcement both vertically and circumferentially due to the temperature gradient through the concrete. Formulas for combining the stresses due to dead and wind (or earthquake) loads with the stresses due to temperature are included in the specification, together with reccommended allowable stresses in the concrete and reinforcement for the various stress combinations. The specification refers to the ACI "Building Code Requirements for Reinforced Concrete" (ACI 318) for applicable requiremens with supplimental provisions to take care of the special requirements for concrete chimneys. Construction requirements are generally in accordance with ACI 318. However, design assumptions are based on working strength rather han ultimate strength procedures.