Title:
Precast Concrete Units Used as Forms
for Cast-in-Place Concrete
Author(s):
ACI Committee 347
Publication:
Journal Proceedings
Volume:
66
Issue:
10
Appears on pages(s):
798-813
Keywords:
architectural concrete; bond (concrete to concrete) ; bridges (structures); buildings; concrete blocks; concrete construction; concrete dams; connections; ferrocements; floors; formwork (construction);hydraulic structures; inserts;joints (junctions).
DOI:
10.14359/7405
Date:
10/1/1969
Abstract:
Precast concrete units, unreinforced, reinforced, or prestressed, are used as forms for both cast-in-place and precast concrete. This report deals with precast units as forms for cast-in-place work, showing how such units are used: (a) as structurally adequate for applied loads and concrete pressures without support except ties and alignment braces, or (b) as liners for forms made of other materials. These concrete forms may either be removed after casting or remain in place as a permanent part of the structure. A principal application of stay-in-place forms has been as architectural facing, but some stay-in-place forms also become structurally composite with the cast-in-place concrete. This report surveys development of various types of precast forms including ferrocement and facing slabs for mass concrete and hydraulic structures, but concentrates on structural and architectural uses which have been most prevalent in the United States and Canada. Typical formwork installations are described and factors influencing their use are discussed. Also, design and construction requirements for this type of formwork are outlined and suggestions are made for handling, erection, and use of precast forms. Recommendations are given for treatment of joint and connection details and for bond and anchorage of the form units.