GFRC Durability, Resilience and Sustainability
Designing for resilience, durability and sustainability is the approach we provide to address uncertainty – climatic, dynamic, and economic. Long term ownership requires a long-term vision.
- Sustainability we define as the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building’s life-cycle.
- Durability we define as the ability of a building and its parts to perform its required functions over a period of time and under the influence of normal conditions.
- Resiliency we define as the ability to adapt to changing conditions and prepare for, withstand, and rapidly recover from disruption.
Glass fiber reinforced concrete is an ultra-efficient composite system composed of a light gauge steel frame and a high-density thin precast shell. This is in contrast to an 8″ concrete wall system that is inefficient in material, weight, and performance. The material efficiency of GFRC reduces the amount of embodied energy and embodied carbon.
- 1.5 kWh/SF of embodied energy for GFRC compared to 20.4 kWh/SF for 8″ precast
- 0.2 lbs/SF of embodied carbon for GFRC compared to 2.7 lbs/SF for 8″ precast.
The three primary forces affecting the durability of a building envelope are water, heat, and UV radiation. Building envelopes are affected by water in two ways – rainwater and vapor drive – both are controlled by GFRC.
- ASTM E331 (Water Penetration) GFRC has 0 static water infiltration at 10.0 PSF
- AAMA 501 (Exterior Wall Test Methodology for Leakage) GFRC has 0 dynamic water infiltration at 100.0 MPH
- ASTM E96 (Water Vapor Transmission) GFRC has 0.036 Perm of vapor permeance
The exterior of our GFRC wall system is high-density precast concrete that is inert to UV degradation with a colorfast integral finish. Furthermore, the panel is designed to accommodate thermal movement and mitigate thermal conduction via an integral mineral wool thermal barrier. The surface of the GFRC skin is treated with a fluorosilane sealer that reduces the surface wetting and thereby the dirting of the GFRC. This has the benefit of keeping the façade clean longer, and reducing the maintenance cycle of our GFRC.
The durability of GFRC has been tested in multiple technical studies, most importantly in “A Review of the Durability of Glass Fiber Reinforced Concrete (GFRC), Design, and Applications”, which provides the following conclusion:
The design principles first established for GFRC were based on projected long-term strengths for GFRC derived from accelerated aging tests. This has proved to be conservative because real time actual weathering has shown better than the projected long-term performance. Also the initial GFRC composite was based on sand:cement mixtures and this has now been superseded by other formulations containing either admixtures, such as acrylic copolymer and pozzolans, or cements other than Portland cement all of which offer GFRC composites that have significantly better long term performance in many different environments. It is believed that any questions about the durability of GFRC can now be put to rest and GFRC research should concentrate on developing more ambitious design procedures and more challenging applications for GFRC.
We stand behind the durability of our materials and designs by providing a 10-year system warranty – this is in contrast to almost all other unitized wall systems and certainly way beyond what is provided with a site build wall.
Natural and manmade hazardous events, such as hurricanes and fires, can impose a devastating cost upon buildings. Building designs, therefore, need to consider effective and efficient ways to develop resilient building envelopes. Establishing the tradeoffs between performance and cost requires evaluating the relationships between the initial cost of providing the building systems and the performance over the life of the asset. This value needs to be considered from a total cost of ownership, not just a traditional first cost estimate. The total cost of ownership must consider such factors as recovery costs from a disruption, structural efficiencies, and operational savings (energy and maintenance). Our GFRC has passed TAS 201 Large and Small Missile Test Standards, TAS 202 Uniform Structural Load Standards, and TAS 203 Uniform Cyclic Pressure Test Standards. These are the Test Standards required for a Miami-Dade Product Approval. Furthermore, our wall system has a 2 hours fire rating per UL CWS-2066. In addition, we have designed our GFRC wall system to meet GSA blast-resistant design criteria of pressures of 8psi, and impulses of 36psi-msec.
Once constructed, a building becomes a machine that needs to be fed. The more durable and resilient the building the longer it is around. The longer the building is around the more energy it consumes, and therefore, durable buildings must be energy efficient in order to be sustainable. Durability in conjunction with energy efficiency are the requisites of sustainability and long-term value. Building Blocks’ unitized GFRC wall system delivers on the three criteria of Sustainability, Durability, and Resiliency in a smart design paired with our commitment to the customer’s success.