As-Cast Concrete Finishes: Specifications, Defects, and Repairs-As-Cast Concrete Finishes Specifications, Defects, and Repairs (PDF)

As-Cast Concrete Finishes Specifications, Defects, and Repairs (PDF)

Pdf Summary

The document presented is a comprehensive guide on the specifications, defects, and repairs related to as-cast surface finishes in concrete structures, notably focusing on how visible effects of consolidation might be categorized as defects. Authored by Kim Basham, PhD, PE, FACI, and presented at the ACI 2018 Spring Convention, it delves into the standards established by the American Concrete Institute (ACI) regarding surface finishes, detailing a variety of finish types recognized within industry standards such as ACI 301, ACI 117, and ACI 347.<br /><br />Concrete surfaces are usually specified in terms of texture and appearance based on their intended visibility and structural importance. Different finish types, such as rough-form, smooth-form, and architectural form, have distinct characteristics and application requirements outlined in the documentation. Precise instructions on form-facing materials and the treatment of surface imperfections, such as voids, projections, and tie holes, are provided with examples from standards like ACI 301-10.<br /><br />Issues like honeycomb, air voids, and form offsets are identified as common defects arising from inadequate consolidation and placement techniques. The document provides guidelines for proactive measures to prevent these problems, emphasizing the need for proper vibration during concrete placement to ensure integration and remove air entrapment, thus avoiding potential defects such as cold joints and surface irregularities.<br /><br />The document outlines repair methodologies for defects when they occur, such as patching surface voids and addressing honeycombing using hand applications or form-and-pour methods. There’s a notable focus on the responsibilities involved in defects – from investigation to repair, including the roles of different stakeholders such as engineers, contractors, and owners.<br /><br />Overall, the text serves as a robust guideline for professionals involved in concrete construction, providing clarity on the standards, anticipation of defects, and ensuring successful implementation of repair strategies to meet visual and structural concrete surface expectations.

Keywords

concrete structures

as-cast surface finishes

defects and repairs

ACI standards

honeycomb

surface imperfections

consolidation techniques

repair methodologies

architectural form

vibration during placement