Join us for our monthly meeting via Zoom as we discuss APT DC business and plan for upcoming events!

Olson Engineering (Larry Olson, PE, President and Chief Engineer, and Lyndsay Hazelwood, CPG, Senior Project Geologist) present a webinar on Nondestructive Evaluation (NDE) Methods for condition assessment of masonry and historic stone buildings with relevant case histories. This webinar will focus on NDE methods such as Impact Echo, Spectral Analyses of Surface Waves, Infrared Thermography, Ultrasonic Pulse Velocity, and Ground Penetrating Radar. Presenters will detail how one-sided testing can be done to detect cracking damage with Impact Echo (IE) tests while depths of perpendicular cracks and elastic moduli can be measured using Spectral Analyses of Surface Waves (SASW) and demonstrate how infrared Thermography (IR) imaging can be used to find damaged areas via observed temperature differences. Presenters will also focus on accessible locations and how ultrasonic/Sonic Pulse Velocity (UPV/SPV) can be done with multiple crossing test pages to provide velocity tomography images of internal material conditions. Finally, attendees will learn more about Ground Penetrating Radar (GPR) and how it is used to map out embedded reinforcement and grout/void conditions in the cells of concrete block masonry. 

Specific case studies include but are not limited to: NDE of the Lincoln and Jefferson Memorials, marble column volutes, and masonry of a historic church.

One (1) AIA HSW Credit is available.

Please note: Video will be recorded.

APT DC invites you to join us for our Annual Summer Picnic! This year, we will celebrate at Historic London Town at the Phillips Pavilion. Nestled along the scenic South River, the open-wall pavilion offers a beautiful outdoor setting for our annual picnic! 

Prior to the picnic, a private tour of the William Brown House will be given from 10:00am - 11:00am. Spots are limited to 20 people, however attendees unable to attend the tour will still have all-day access to the grounds and are encouraged to explore before/after the picnic!

More about the guided tour: William Brown House Tour | Historic London Town & Gardens | Edgewater MD

Historic London Town: History Museum & Gardens | Historic London Town and Gardens | Edgewater Maryland

Food/Beverages: APT DC will have a taco bar from Señor Chile as well as water and sodas.

What to bring: sunscreen, bug spray, extra water.

Parking: Free parking is available.

Pets: Leashed dogs are permitted

Registration will open Summer 2026.

For more information about submitting an abstract, please visit https://aptdc.org/Symposium.