The leading voice for the crushed stone, ready mixed concrete, sand and gravel, and cement industries' community.
PELA is a 10-month hybrid program with online and in-person educational sessions and networking opportunities.
Careers in the Aggregates, Concrete & Cement Industries
The Pennsylvania Aggregates and Concrete Association (PACA) is the industry’s unified voice, representing more than 200 member companies across the state.
Creating a unified and strong voice for our industry.
PACA monitors and analyzes local, state and federal regulations and advocates for a balanced approach by the regulators.
PACA builds a bridge between our members and our partners at PennDOT, and the Pennsylvania Turnpike Commission along with Pennsylvania’s construction industry to further the use of our materials to the benefit of the commonwealth.
One of the most effective tools in government relations for an industry is a robust advocacy/grassroots strategy.
In the last legislative session, we contributed over $275,000 to our political champions.
November 2025 at Hotel Hershey in Hershey, PA (PACA members only event).
PACA offers comprehensive concrete certification programs for ACI, NRMCA, and PennDOT in the central Pennsylvania area.
Membership has its privileges - most of PACA's events are open to PACA members only.
PACA conducts numerous education and training events during the year.
Choose concrete for your next parking lot project.
Streets built with concrete are built to last, consider concrete for your next project.
Concrete's strong, resilient and the choice for your next building or bridge.
PACA works with the National Ready Mixed Concrete Association (NRMCA) to convert your parking lot or building project to concrete without hurting your bottom line.
PACA drives a member-approved strategic plan to increase market share and engages specifiers and owners on the value of concrete in their projects.
This program provides free continuing education to the design and specifying communities. There are currently four courses available, ranging from 30 minutes to 60 minutes focused on the cement, aggregates and concrete industries. You'll receive a certificate of completion once you pass a quiz. The bookmarking feature allows you to leave the course and resume where you left off when you return.
According to the U.S. Environmental Protection Agency (EPA), construction and demolition (C&D) waste totaled 600 million tons in 2018. Demolition accounted for about 90% of the total, while construction accounted for about 10%. 455 million tons of C&D debris went to “next use.” 145 million tons went to landfills.
Around the world. construction and demolition waste is big business. One projection shows the global C&D waste market growing from $108.74 billion in 2021 to $142.92 billion in 2028. There is a massive disparity in rates of C&D waste recycling. It is more than 90% in Italy and the Netherlands, for example, but less than 10% in Finland and Greece. In Brazil, the recycling rate is 1%.
A lot of this waste is concrete. Recyclers crush and process some of it to produce recycled concrete aggregate (RCA). It is not always necessary to crush the concrete to reuse it. Broken slabs may line ditches to reduce erosion, for example.
At present, it is not practical to use RCA instead of natural aggregate (NA) in most construction projects. There are two key obstacles. First, RCA absorbs moisture at a higher rate. Second, excess quantities of adhered mortar may compromise performance. Porous adhered mortar weakens the bond between old and new concrete matrices. In fact, the compressive strength of RCA concrete is about 10-30% less than with OPC.
Previously, studies demonstrated that graphene additive improved compressive and tensile strength in concrete made with natural aggregates. Now, research shows that graphene oxide can deliver NA-level performance in RCA concrete. Other nanotechnologies show promise in improving durability and mechanical strength. Examples include carbon nanotubes and carbon nanofibers. However, graphene oxide is far more affordable.
At present, recycled crushed concrete accounts for about 5% of all aggregate. About two-thirds of RCA becomes road base. Another 9% goes into asphalt, while 6% is used in new concrete mixes. Therefore, there’s ample opportunity to redirect RCA supplies to new concrete mixes. It simply needs to sufficiently perform to make it a viable alternative.
Supplies of crushed concrete vary across the country. In some areas, supplies are fully recycled. For example, the Florida Department of Transportation (FDOT) says that “all the crushed concrete that is produced in the state is currently being utilized.”
The FDOT also sounds a word of caution. The quality of crushed concrete varies “depending on where it originates and how it is processed.” It is also vital that RCA does not contain toxic contaminants like asbestos or lead.
The cost to transport aggregate is also a consideration. A local RCA source might compete favorably with natural aggregates coming from further away. However, using local RCA requires a local ready-mix plant capable of handling it.
Graphene continues to secure its status as a modern-day miracle material. Imagine one substance used in everything from batteries to lubricants, and from superconductors to body armor. It can also strengthen concrete. This should not be surprising, given that it is 100 times stronger than steel.
Previous research focused on graphene oxide (GO) added to concrete with natural aggregates. There is now a study that examines the use of a graphene additive with RCA. Is it possible to replace NA with RCA? This research answers, “Yes!” Relatively small amounts of GO in RCA concrete deliver the performance required.
Researchers examined a variety of concrete mixes. The control mix was 70% ordinary Portland cement (OPC) and 30% fly ash. Other mixes featured 100% RCA. They also included 0.0, 0.05 and 0.10% graphene oxide.
The team determined that an RCA mix with just 0.1% graphene oxide (GO) and balled-milled graphene oxide (GObm) replicated the mechanical and durability properties of the control mix. The RCA mix also had a better economy index and higher overall desirability function. Increasing graphene levels improved compressive strength, electrical resistivity and ultrasonic pulse velocity. Increasing graphene also reduced sorptivity and initial surface absorption.
Of course, RCA concrete with graphene requires reliable GO supplies. Unfortunately, volume production has been lacking to this point. An article published by the Institution of Mechanical Engineers asserts that, “The biggest challenge for many graphene producers has been delivering consistency of quality and supply volume.”
First Graphene Ltd. has found success in addressing these quality and supply challenges. It uses a proprietary electrochemical exfoliation process to produce high-purity graphene. First Graphene found a way to overcome the problem of agglomeration. It uses “water-based admixtures containing pre-dispersed graphene nanoplatelets.” In December 2021, it filed for a patent in the UK to protect its process.
First Graphene’s R&D center is at the University of Manchester in the UK. Its initial production facility is in Australia. The plant can produce 100 tons of high-purity graphene per year. Management asserts that it is possible to replicate and scale the plant at other locations around the world.
Aggregates constitute about 60-80% of a typical concrete mix. Now, research shows that it is possible to replace natural aggregates with RCA, as long as a relatively small amount of graphene is added. Long term, the viability of RCA concrete may also lead to more recycling of concrete. Specifying RCA concrete may also give companies another way to achieve their sustainability goals.
The Pennsylvania Aggregates and Concrete Association monitors new developments in the industry. This includes research into the sustainability of concrete. For help with questions about your upcoming concrete project, please contact us.
February 22, 2024
Proficient carbon calculations are increasingly important as “Buy Clean” legislation proliferates. New York and Colorado are among the states that now require carbon calcs for public projects. An estimated 40% of emissions are from the built environment. According to one estimate, the planet’s total building floor area will double by 2060. This makes the concrete industry a key player in the quest for net-zero emissions products and projects.
February 15, 2024
The Natural Resources Defense Council (NRDC) notes that cement production is “so carbon intensive that even though cement makes up less than 15% of concrete by weight, it accounts for 90% of concrete’s carbon footprint.” The use of fossil fuels to fire cement kilns is a key source of these carbon emissions.
February 08, 2024
In the quest for reduced greenhouse gas (GHG) emissions, everyone has a role to play. In the concrete industry, this includes everyone from manufacturers to contractors, and from trade associations to governments. Here is a review of some of the major initiatives impacting concrete’s sustainability.
February 01, 2024
Ordinary Portland cement (OPC) requires high-temperature calcination of limestone. It is possible to use various emissions-reducing pozzolans in concrete. Fly ash comes from coal-fired power plants. Ground granulated blast furnace slag (GGBFS) comes from steel mills. Another SCM is metakaolin derived from kaolin.
The program is delivered in one (1) module and it should take approximately 30 minutes to complete. You will receive a certificate of completion once you pass the quiz. The bookmarking feature will allow you to leave the course and resume where you left off when you return.