Rheology Limits for Grout Materials used for Precast Bent Cap Pile Pockets in Hot Weather

This research aims to evaluate grouted pile pocket connections to gather subsidiary information on limiting factors - anticipated throughout the construction process - to assist the Structures Design Office in the standardization process of Precast Intermediate Bent Caps. It is the objective to identify or establish preliminary limits for the acceptability of grout properties and geometrical restrictions to ensure adequate consolidation of gravity fed grout for the proposed connection detail. The study intends to obtain such information through the simulation of different flow-spaces (gaps between pile and pocket surfaces) and varying grout temperatures throughout the placement process, while documenting the flow and final air voids. Additionally, it is the goal of this project to qualitatively study and rate the suitability of plywood surfaces for mockup specimens. This project focuses on the rheologic properties of the grout material under varying placement temperatures and different flow-spaces geometries. Initially, a minimum of six (6) pile pocket mockup specimens are proposed to compare three (3) temperature ranges, two (2) minimum flow-space openings, and two (2) surface properties of the pile model. Depending on the findings, five (5) additional mockup specimens will be prepared to further study minor and /or major effects. Due to the limited number of specimens, the utilized grout material for the mockup specimens will be limited to a single product; BASF Masterflow 928. This grout material was chosen because previous steel reinforced concrete (SRC) mockup bridge deck panel tests and the Florida accelerated bridge construction (ABC) demonstration project (US90 over Little River and Hurricane Creek) employed BASF Masterflow 928 for all grouted connections and it is anticipated to be used for similar projects in the future. A proper flow and void analysis is essential to this project and will be facilitated through transparent and translucent molds - the outer fromwork for all mockup specimens will be constructed from clear acrylic sheets. However, the pile heads will generally be modeled from plywood, except for the control specimen (MUl), as contractors would typically utilize plywood for preconstruction grouting demonstrations and acceptance tests.