GPR Scanning for Artwork Design and Construction

Carrasquillo Associates (CA) performed work related to ground penetrating radar (GPR) scanning for artwork to be installed. Prior to construction, CA scanned and mapped areas around the perimeter and approximately 900 sq. ft. of the art zone’s interior to determine appropriate places for through drilling between double tee stems and embedded anchors in double tee stems. After reviewing available construction documents, drawings, and project related material, CA completed extensive scanning of the parking deck using high resolution GPR equipment. CA mapped the location of precast double tee stems and embedments in the parking deck. Embedments and items found on the underside of the slab were identified as “no drill zones” and the extents of the double tee stems were also mapped. The project was a great success with over 900 sq. ft. scanned, and only one drilled hole encountering an unforeseen embedment.

Use of Supplementary Cementitious Materials at the McMurtry Building

This project involved consultation for the production of sustainable, architectural, white concrete for the construction of the McMurtry Building at Rice University in Houston, Texas. The many challenges associated with the architectural and structural concrete included the use of seventy percent cement replacement with slag as a supplementary cementitious material while achieving adequate strength gain during early ages to meet the demands of the construction activities. CA developed recommendations on the selection of the concrete materials and the concrete mixture proportions, guidelines for the batching and mixing of the concrete, formwork details, form release agents, and concrete consolidation procedures. The final selection was based on the casting of several mockups. Other issues addressed included recommendations for the protection of the architectural concrete during other construction activities such as acid wash of the CMU installations.

LEED Certification at LCRA Red Bud Center

CA provided sustainable construction consulting services to the general contractor for the construction of the LCRA Red Bud Center’s architectural concrete elements including textured exposed architectural concrete walls. CA’s consulting work included the review and evaluation of the concrete specifications, plans, and drawings.  CA then developed recommendations for the concrete mixture proportions, formwork, and concrete placement, in particular consolidation practices to meet the project requirements and most importantly the architect’s vision and aesthetic value of the exposed concrete. The architecturally exposed concrete walls were required to exhibit a textured form finished pattern and appearance similar to that observed in the Tom Miller Dam adjacent to the LCRA Red Bud Center built over 60 years ago. CA was also involved in the evaluation and concrete repair of the finished concrete walls. The design requirements incorporated the implementation of sustainable construction strategies and practices required to meet the standards of the United States Green Building Council. The facility achieved USGBC LEED® Gold Certification and Four-Star Rating from the Austin Energy Green Building Program.

Structural Evaluation and Testing of a Parking Structure

Work performed on a parking structure located in Plano, Texas, encompassed a two phase investigation. Phase I consisted of investigating the cause of cracking occurring in the precast, prestressed double tee beams which resulted in the repair or replacement of several double tees. The forensic structural engineering investigation included a condition assessment of the parking garage structure, evaluation of the double tees removed from the structure, sampling of the concrete, non-destructive testing, petrographic examination, and analytical testing. Phase II consisted of investigating the cause of distress in the architectural precast concrete elements by performing a condition assessment and evaluation of the architectural precast elements in-place. It involved determining the adequacy of the erection details, connections, and the overall structural integrity of the precast architectural members.  CA’s forensic consulting work on this project involved performing a structural analysis, sampling, testing, and petrographic examination of the concrete, the review of concrete production and construction practices, and the development of recommendations for rehabilitation and maintenance of the parking garage structure.

Concrete Materials Consulting for the Modern Art Museum of Ft. Worth

In May of 1997, the world renowned architect, Tadao Ando, was selected as the architect for the Modern Art Museum’s building in Fort Worth, Texas. The Museum’s 150,000 square foot building sits on an 11-acre property. CA provided concrete materials consulting services for the production and construction of the architectural concrete structure including, among others, material selection, concrete mix proportions, batching, quality control, formwork, and consolidation. Notable features of the building included a natural setting utilizing existing major trees on site augmented by additional trees; shrubs and plant materials native to North-Central Texas; three gallery pavilions that appear to float above a shallow reflecting pond to the north and west; double skin or envelope inner structural walls of cast concrete to protect interior gallery spaces and support large projecting roof planes above; outer glass and metal panel walls to provide public circulation areas from which to view the museum’s landscaped exterior and reflecting pond; and immense concrete roof overhangs, supported by Y-shaped columns on the east side to help shade interior spaces surrounded by 36 foot glass curtain walls constructed with energy efficient insulated glass units.

Architectural Concrete Quality Control and Quality Assurance Program at the Mexican-American Cultural Center

This project was a joint effort between the City of Austin and Desarrollo Integral de Inmuebles, S.A. de C.V. in Mexico. Construction consisted of white precast architectural concrete panels produced in Mexico and white cast-in-place architectural concrete cast in Austin, Texas. Initially, CA was retained to investigate the cause of concrete cracking and failure of some architectural precast panels upon delivery and/or erection of the panels in the project. CA determined that the cause of the cracking was related to the reinforcement and anchorage details associated with the lifting hooks. CA evaluated and tested the anchorage detail and visited the contractor in Mexico to help implement changes. In addition, CA worked with the owner in the development and implementation of the quality control and quality assurance procedures during the construction of the project. CA was also retained to determine the cause of inconsistencies in the color and appearance of the cast-in-place architectural concrete. CA developed recommendations to achieve the specified quality of the architectural concrete construction restoring the uniformity within the architectural concrete in the project in addition to facilitating the progress of the construction activities. Of great significance, CA’s work resulted in alternatives and recommendations to adequately fabricate and install the architectural precast panels meeting the needs of the contractor to achieve the specified project requirements.