Sessions and Events

Sessions & Events 

C = Duke Energy Convention Center; H = Hyatt Regency Cincinnati

Novel Techniques and Advances in Load Testing Concrete Structures

Mon, October 21, 2019 4:00 PM - 6:00 PM, C-Junior Ballroom C

This session will introduce attendees to new techniques in load testing of concrete structures. Such techniques include load testing structures where shear is the expected covering limit state, and where nondestructive testing or monitoring supplements load test results.
Learning Objectives:
(1) State how nondestructive testing can aid in load testing concrete structures;
(2) Explain how load testing has been performed on structures where shear may be the governing limit state;
(3) Describe performance evaluation of repaired structures through load testing;
(4) Identify challenges facing engineers when load testing is selected as a means of strength evaluation.

Load Testing of In-service Structures: Case Studies and Lessons Learned

Presented By: Brian Greve
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: This presentation provides an overview of load tests conducted to evaluate the condition of in-service structures, with a focus on the monotonic (24-hour) load test method. Examples of recent load tests will be presented to highlight different applications. Different phases involved in planning and execution of load tests will be discussed including investigating the need to conduct a load test, field assessments, structural analysis, determining load test protocol, and implementing the load test. This presentation will also discusses challenges and lessons learned from unique load tests which may be of interest to both practitioners as well as the research community and those with general interest in field load testing.

Load Testing – Changes in ACI 318-19 – Integration and Coordination between Committees

Presented By: Keith Kesner
Affiliation: CVM Engineers
Description: Load testing has been an integral part of the ACI 318 Standard since the first version was published in 1941. Since 1941, the accepted procedure for load testing has basically involved application of a load to the element for a defined period of time with acceptance (passing) of the load test was based upon a deflection limit and / or recovery of deflections. The load and acceptance criteria have only been slightly changed since the 1963 version of ACI 318. The quasi-equilibrium of load testing procedures was altered with the publication ACI 437.2 “Code Requirements for Load Testing of Existing Concrete Structures”, which allowed the use of both cyclic and traditional static load testing. Adoption of ACI 437.2 into the ACI 562-13 “Code for Repair and Rehabilitation of Existing Concrete Buildings” created a situation where two ACI codes allowed different procedures for load testing of structures. The presentation will describe how three ACI committees worked on the load testing procedures adopted in ACI 318-19, which eliminated the conflict between ACI 318 and 562.

Load Testing of a Precast Concrete Tub Stadium Riser

Presented By: Jeremiah Fasl
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: During installation of precast concrete tub risers at a collegiate stadium in the United States, cracking was observed shortly after installation. Because the precast concrete risers were cracking within a cantilevering portion of the stadium, the Engineer-of-Record was concerned with the safety and durability of the risers and requested that one of the risers be load tested in accordance with the requirements of ACI 318-11. As such, a riser was instrumented with multiple string potentiometers to measure the deflection response as the riser was loaded with water (using industrial sized totes) to the total test load magnitude. This presentation will discuss the condition of the risers, as well as the methodology and results of the load test.

Load Testing After Strengthening of a Pre-stresses Double Tee Beam that had Failed in Shear

Presented By: Nestore Galati
Affiliation: Structural Technologies
Description: This presentation discusses the results of a load test performed on one double tee (DT) beam located at the roof level of a parking garage in Virginia. The roof floor framing consists of precast, pre-stressed, concrete double tee (DT) beams supported by precast concrete girders and precast columns. Following a heavy snow storm, a landscape contractor had piled up all the snow on the roof on two DT beams which were exhibiting signs of imminent shear failure. The strengthening of the beams consisted in restoring the shear integrity of the beams and strengthening them with externally bonded FRP. A load test was performed approximately a week after the installation of the FRP strengthening. The load test was performed following the procedure in ACI 437.2-13“Code Requirements for Load Testing of Existing Concrete Structures and Commentary”, using the monotonic test protocol (ACI 437.2-13 Section 5.3). The load test was performed using hydraulic jacks placed in a configuration to simulate the full design shear and moment at the critical section. Since the beams were located on the roof the structure was monitored 24 hours prior testing to discount the effects of the temperature on the load testing.

Development of Database for Structural Load Tests

Presented By: Mohamed ElBatanouny
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: ACI currently adopts two methods to conduct structural load tests for new and existing structures namely the monotonic (24-hour) load test and cyclic load test. The acceptance criteria for both methods are generally based on comparing residual deflections after the load test to maximum deflections recorded during the load tests (or load cycle for the cyclic load test). Up to the latest code editions (ACI 318-14 and ACI 437-13) the maximum deflection was also compared to a calculated value, which differed between the two codes. Therefore, there is a need to collect test data to evaluate the equations used to assess the maximum deflection measured during the load test. ACI 437 Committee - Strength Evaluation of Existing Concrete Structures recently formed a new subcommittee to carry out this task. This presentation offers a brief overview of the committee and provides an update on the ongoing load test data collection effort.

Upper Level Sponsors

Advance Ready Mix Concrete, Inc.
Anderson Concrete Corp.
Dugan and Meyers LLC
Euclid Chemical
Forta Corporation
Greater Miami Valley Chapter – ACI
Hilltop Companies
Irving Materials, Inc.
Indiana Chapter - ACI
Largo Concrete, Inc.
Lebanon Chapter – ACI
Lithko Contracting, LLC
Messer Construction Co.
Northern California & Western Nevada Chapter - ACI
PlanGrid - an Autodesk Company
Quebec and Eastern Ontario Chapter – ACI
RMD Kwikform
Ruttura & Sons
San Antonio Chapter – ACI
Terracon Consultants, Inc.
TWC Concrete Services, LLC
Webcor Builders
West Michigan Chapter – ACI