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This reference specification covers quality assurance inspection services for preplacement, placement, and post-placement of concrete construction. This reference specification can be made applicable to a particular construction project by citing it in the inspection services contract. The specifier shall supplement the provisions of this reference specification as needed by specifying individual project requirements in the inspection services contract. The materials, processes, quality control measures, and inspections described in this Specification should be tested, monitored, or performed as applicable only by individuals holding the appropriate ACI Certifications or equivalent. Keywords: accreditation; certification; concrete construction; inspection agency; placement; post-placement; preplacement; quality assurance; quality control; special inspections; specification.

In FA15 and FA30 pastes, a higher chloride disassociation was observed in NaCl solutions than in CaCl₂ and MgCl₂. The results for SG25 and SG50 revealed that, regardless of cation type, the inclusion of higher slag increased the chloride binding and reduced the percentages of released bound chlorides. The desorption results revealed that an increased silica fume content from 5 to 10% enhanced the chloride binding capacity and dissociation behavior. The inclusion of SCMs is a trade-off between achieving higher binding and releasing higher chloride content and lowering the system's buffer capacity due to the consumption of a considerable amount of portlandite. Chloride disassociation is influenced by the binder composition, cation type, and pH.

Pour-backs at post-tensioning (PT) tendons anchorage ends provide corrosion protection to the anchorage hardware, improving the durability of post-tensioned structures. However, the interface may serve as a pathway if deficiencies are present between the PT structure and the pour-back material, providing a route for water and other factors that could negatively affect the structure's integrity. Therefore, this research addressed the need to develop a pour-back material guidance and test methods to improve the bond at the interface.

A reliability-based calibration of a strength reduction factor for one-way shear strength limit state was not justifiable in the past because of well-founded concerns about the level of safety associated with the ACI 318 traditional one-way shear strength expressions—particularly for large and lightly reinforced beams and slabs—which were first introduced in 1963. After a sustained, collaborative effort of several ACI technical committees (318-E, 445, and 446) to address these safety concerns, improved one-way shear strength expressions were adopted in ACI 318-19. The ACI 318-19 one-way shear design equations are a significant improvement relative to the previous shear design equations in former editions of the ACI 318 building code requirements; however, the reliability of members regarding one-way shear strength limit state remained unknown. Therefore, the objectives of this study were: (1) to provide a statistical basis for improving the strength reduction factor for one-way shear, and (2) to propose a new strength reduction factor for one-way shear, if justified. In this study, relevant test data available in the literature were collected to characterize uncertainties regarding material mechanical properties and cross-sectional dimensions. Although most parameters were statistically represented in the same manner as in previous ACI 318 code calibration, the in-place concrete strength uncertainty was updated, and the considerations for uncertainty in effective depth were specifically revised for one-way shear strength. A large database of the yielding strength of reinforcing bars of sizes commonly used as shear reinforcement was analyzed, and new statistical parameters were developed. In this assessment, data-driven professional factors, which represent the uncertainty in the analytical model, were used instead of expert opinion estimates as in the past. Several scenarios were considered throughout the analyses: small, medium, and large size members; light, moderate, and heavy longitudinal reinforcement; no, light, moderate, and heavy shear reinforcement; and dead to total load ratios from 0 to 1.

The E-Defense shake table facility, the world’s largest three-dimensional (3-D) full-scale earthquake testing facility, was constructed by the National Research Institute for Earth Science and Disaster Resilience (NIED) in 2005 in Miki, Japan. Since then, over 80 full-scale or large-scale experiments have been conducted to have a better understanding of the effects of earthquakes on structures. In December 2015 and later in December 2018 and January 2019, NIED tested two 10-story reinforced concrete (RC) buildings on the E-Defense shake table. The main purpose of this report is to evaluate these buildings using the current provisions of ACI 318 (2019) and ASCE 7(2017), and to gain better knowledge on the effectiveness and accuracy of these standards. The lateral force resisting systems for the buildings consisted of special reinforced concrete shear walls(bearing wall systems) in one direction and special reinforced concrete moment frames(moment resisting frame systems) in the orthogonal direction. Three-dimensional elastic models are created using the structural engineering software ETABSⓍR 2018. Model results showed that, for the 2015 test structure, beam and column shear reinforcement and transverse reinforcement for special boundary elements (SBEs) were modestly less than required by ACI 318-19 provisions. Although diagonal shear cracks were reported within some beam-column joints after the 2015 experiment, current provisions of ASCE 41-17 were not able to predict these joint shear failures, although more detailed approaches proposed in the literature suggested joint damage might occur. For the 2018 building, joint and column transverse reinforcement and column-to-beam strength ratios were increased such that they satisfied ACI 318-19 provisions; however, special boundary elements transverse reinforcement and beam shear reinforcement near beam ends still were modestly less than required by ACI 318-19.