National Concrete Authority - Concrete Construction Reference

Concrete construction encompasses the design, placement, curing, and long-term maintenance of portland cement–based structures across residential, commercial, and civil applications in the United States. This page defines concrete construction scope, explains the mechanisms governing structural performance, maps common project scenarios to decision frameworks, and connects readers to the network of member resources that cover concrete and related construction verticals nationwide. Understanding how concrete behaves — and how regulatory codes govern its use — is essential for owners, contractors, and inspectors navigating the broader construction landscape.

Definition and scope

Concrete is a composite material consisting of portland cement, coarse and fine aggregate, water, and — in modern commercial practice — chemical admixtures and supplementary cementitious materials (SCMs) such as fly ash, slag cement, or silica fume. The American Concrete Institute (ACI), through ACI 318, establishes the primary structural design requirements for reinforced concrete buildings in the United States. The International Building Code (IBC), maintained by the International Code Council (ICC), incorporates ACI 318 by reference and governs building permits in the majority of US jurisdictions.

Scope boundaries within concrete construction divide into four principal categories:

1. Structural concrete — load-bearing elements including footings, foundations, columns, beams, slabs, shear walls, and retaining walls governed by ACI 318 and ACI 301.
2. Flatwork — driveways, sidewalks, parking lots, and floor slabs not classified as structural by ACI 318 but still subject to local codes and ASTM material standards.
3. Specialty concrete — shotcrete, high-performance concrete (HPC), self-consolidating concrete (SCC), and lightweight concrete, each governed by ACI committee standards (ACI 506 for shotcrete; ACI 213 for lightweight).
4. Repair and restoration — governed by ACI 562 and the International Concrete Repair Institute (ICRI) Technical Guideline No. 310.2R, addressing surface preparation, material selection, and application methods.

The National Concrete Authority serves as the primary reference hub for concrete construction topics across this network, covering mix design, structural applications, and project classification. For coating systems applied to concrete surfaces, the National Concrete Coating Authority provides dedicated reference content on epoxy, polyurea, and polyurethane systems. The concrete vertical group page maps how these resources interconnect.

How it works

Concrete achieves structural capacity through a chemical process called hydration, in which calcium silicate compounds in portland cement react with water to form calcium silicate hydrate (C-S-H) gel. ACI 318-19 defines minimum specified compressive strength (f'c) requirements by element type; for example, footings in structures assigned to Seismic Design Category D, E, or F must reach a minimum f'c of 3,000 psi (approximately 20.7 MPa), per ACI 318-19 Section 19.3.3.

The construction sequence for a reinforced concrete element follows discrete phases:

1. Design and specification — Structural engineer of record (SER) prepares drawings and specifications compliant with ACI 318; mix design is submitted per ACI 301 Section 4.
2. Forming — Temporary formwork sized per ACI 347 supports concrete until it achieves adequate strength; formwork loads are governed by ASCE 37.
3. Reinforcement placement — Deformed steel rebar (ASTM A615 or A706) or welded wire reinforcement (ASTM A1064) is positioned and inspected against approved shop drawings.
4. Concrete placement — Ready-mixed concrete delivered per ASTM C94 is placed, consolidated by internal vibration per ACI 309, and finished to specified tolerances (ACI 117).
5. Curing — Curing maintains moisture and temperature for a minimum of 7 days for Type I/II cement per ACI 308; inadequate curing reduces 28-day compressive strength by up to 40%, according to ACI 308R-16 data.
6. Inspection and testing — Special inspection per IBC Chapter 17 requires continuous or periodic observation by a qualified special inspector; standard test cylinders are cast per ASTM C31 and broken at 28 days per ASTM C39.

The regulatory context for construction page expands on how federal OSHA standards (29 CFR Part 1926 Subpart Q) overlay state-level permit requirements for concrete formwork and shoring operations.

Foundation Authority focuses specifically on concrete foundation systems — spread footings, mat foundations, and drilled pier elements — making it a key companion resource for below-grade concrete work. The National Foundation Authority extends that coverage to national-scope foundation reference content, while Foundation Repair Authority addresses diagnostic and remediation pathways for distressed concrete foundations. These three member resources define the foundation vertical group alongside each other.

Common scenarios

Commercial slab-on-grade projects represent one of the highest-volume concrete applications in the US. Minimum design requirements are governed by ACI 360R (Guide to Design and Construction of Slabs on Ground). Vapor barriers, subbase compaction, joint spacing, and post-tensioning options are all classified within that document. Commercial Building Authority covers the broader regulatory and structural context for commercial slab projects. The National Building Authority provides a wider reference frame for understanding how building codes classify occupancy and structural systems that drive slab specifications.

Tilt-up concrete construction, common in warehouse and distribution facilities, involves casting wall panels horizontally on the floor slab and lifting them into position. ACI 551 governs tilt-up design. Panel thickness typically ranges from 5.5 inches to 9.25 inches depending on height, lateral loads, and opening geometry. Alabama Commercial Authority and Georgia Commercial Authority provide state-specific regulatory context for tilt-up projects in the southeastern US, where this construction method is especially prevalent due to climate and industrial real estate demand.

Concrete repair represents a distinct scenario class governed by ACI 562-23 and ICRI guidelines. Surface defects, delamination, carbonation, and chloride-induced corrosion each require different repair strategies. Concrete Repair Authority is the dedicated network resource for repair methodology, material selection, and surface preparation classification. Floor Repair Authority covers a specific subset: industrial and commercial concrete floor repairs including crack injection, grinding, and overlay systems. The National Flooring Repair Authority extends this to flooring systems more broadly, including the decision boundary between concrete substrate repair and flooring overlay replacement.

Decorative and coated concrete scenarios arise in retail, hospitality, and multifamily projects where exposed concrete flatwork or countertop surfaces require polishing, staining, or protective coating. Countertop Authority covers concrete countertop mix design, reinforcement, sealing, and surface finishing in detail. National Concrete Coating Authority addresses industrial and commercial coating systems applied over concrete substrates, including surface profile requirements per ICRI CSP standards.

Demolition of concrete structures introduces additional regulatory complexity. OSHA 29 CFR 1926 Subpart T governs demolition operations, and EPA regulations under the National Emission Standards for Hazardous Air Pollutants (NESHAP) apply when asbestos-containing materials are present. Demolition Authority covers the permitting, notification, and safety framework for concrete demolition projects nationally. Where lead-based paint exists on concrete surfaces, Lead Paint Authority addresses EPA RRP Rule requirements and HUD guidelines that govern disturbance and abatement.

Post-construction cleanup of concrete operations — including form oil residue, curing compound overspray, and concrete slurry from cutting operations — falls under stormwater management rules (EPA NPDES permit program) and local municipal codes. Construction Cleanup Authority maps the regulatory requirements and scope boundaries for post-concrete cleanup on commercial sites.

State-specific regulatory overlays affect concrete construction permitting, inspection frequency, and seismic or wind design requirements. Florida Commercial Authority addresses Florida's High-Velocity Hurricane Zone (HVHZ) provisions under the Florida Building Code, which impose specific concrete mix, cover depth, and inspection requirements beyond IBC minimums. California Commercial Authority covers California Building Code Title 24 requirements, including DSA-regulated school and essential facilities where concrete special inspection requirements are among the most stringent in the nation. Arizona Commercial Authority provides context for expansive soil conditions common to the Sonoran Desert region, which directly affect concrete footing and slab design. Colorado Commercial Authority covers high-altitude and freeze-thaw exposure classifications (ACI 318 Exposure Class F2) that govern air entrainment requirements in Colorado concrete work. Illinois Commercial Authority addresses Chicago's Department of Buildings requirements, which maintain an independent structural concrete inspection program separate from standard IBC Chapter 17 provisions.

Decision boundaries

Selecting the appropriate concrete system, specification, and inspection pathway depends on four primary classification axes:

**Structural vs.