For quality road paving and maintenance projects, the materials must meet the specifications. They should be shipped, stored and handled without separating or going out of spec. They should consistently give the expected results in mix plants, through pavers and under compaction. Asphalt products and additives should be compatible with the project aggregates, and the mixes should give outstanding performance. Mixtures should be resistant to rutting and cracking and they should stand up to traffic, high and low temperatures and moisture. Emulsions should be stable during storage shipping and application, and your emulsion surface treatments should set and cure when you want them to. To achieve all of this, All States Materials Group is proud of its technical capabilities. Our experienced, trained operators use well-maintained, state-of-the-art equipment to make sure you are satisfied with the performance of our products and services. Our capabilities include:
- PG Binder Testing
- Superpave Mix Design
- Liquid Asphalt Emulsion Testing
- Cold Mix Designs
PG Binder Testing
The test methods and specifications developed by the $150 million Strategic Highway Research Program (SHRP) led to the PG binder grading system. The All States laboratory is fully equipped with the latest equipment to run the tests. Our trained technicians use the Brookfield viscometer to test the ease of handling our asphalt binders during pumping and mixing. They operate the Dynamic Shear Rheometer (DSR) to test the ability of our asphalt binders to resist rutting, the Bending Beam Rheometer (BBR) to test the resistance to thermal cracking after aging, the Rolling Thin Film Oven (RTFO) to test the mass loss and aging which occurs during the hot mix process, and the Pressure Aging Vessel (PAV) to simulate long-term aging. Our asphalts are also tested for safety using the flash point apparatus and for solubility in trichloroethylene to rule out the possibility of unwanted additives.
Our researchers use these tests to formulate asphalts to meet the specifications and to give the expected performance as well as quality control on our materials. To meet the more demanding PG grades, we blend materials and use additives to give outstanding performance during mixing, construction and long-term on the road.
Superpave Mix Designs
The Strategic Highway Research Program (SHRP) was a $150 million project sponsored by the federal government. One of its products was Superpave. The Superpave (SUperior PERforming Asphalt PAVEments) system was developed to give highway engineers and contractors the tools they need to design asphalt pavements that will perform better under extremes of temperature and heavy traffic loads. Superpave includes new, performance-based tests, specifications and mix design methods. The Superpave mix design tests indicate how well the mix will perform in the field.
Using the Superpave mix design process, we select aggregates that meet criteria for flat and elongated particles, clay content, fine and coarse aggregate angularity, durability and soundness. We then make several trial blends of differing gradations that meet the Superpave gradation requirements, which are designed to give a strong stone skeleton that will resist rutting, yet include enough asphalt and voids to improve the durability of the mix.
We blend PG (Performance Graded) asphalt with the trial blends and oven treat them to simulate aging. We select the PG asphalt grade that meets the climate, traffic and reliability for the specific project. We then compact the specimens with our state-of-the-art Superpave Gyratory Compactor (SGC). By kneading mixes to simulate construction compaction and traffic loads, the SGC provides specimens that are much more representative of actual in-service pavements. The level or amount of compaction is dependent on the environmental conditions and traffic levels expected at the job site. We also use the gyratory compactor for quality control on our manufactured mixes to verify that the job mix meets volumetric specifications and your satisfaction with the project.
Analysis of the volumetrics of the trial blends lets us determine the optimum trial blend to serve as the design aggregate structure. We then compact a total of six samples of the design aggregate structure using three different amounts of asphalt binder and analyze the density and volumetric properties (air voids, voids in the mineral aggregate, and voids filled with asphalt) to determine the optimal, design asphalt content corresponding to four percent air voids.
The final step is testing for adhesion, bond and susceptibility to moisture damage (stripping of the asphalt binder off of the aggregate by water pressure). To do this, we test SGC compacted specimens for strength before and after soaking in water, calculating the tensile strength ratio.
Our technicians are well-trained and experienced with the Superpave methods and equipment, and they use their expertise to develop the job mix formulas that make sure you are satisfied with your Superpave paving projects.
Liquid Asphalt Emulsion Testing
Oil and water can be mixed. That is our mission. We use additives to chemically stabilize our emulsions to be stable during storage, transport and application, but to break when wanted on the aggregate to give a strong binder. With available new chemistries, water-based asphalt emulsions can now be used for virtually any asphalt paving application. At All States, we know emulsions, with over 25 years of experience of formulating, manufacturing, and using emulsified asphalt in construction. Our researchers and technicians are constantly improving our formulations to give better controlled curing, better adhesion to aggregates, and higher quality, more durable surface treatments and cold mixes.
Our lab mill makes experimental quantities, which we test rigorously. We have full emulsion testing capabilities, to meet all aspects of AASHTO T 59 (Testing Emulsified Asphalt) and T 51 (Ductility of Bituminous Materials). Our technicians test for emulsion Saybolt-Furol viscosity, so that the emulsion is pumpable yet thick enough to give the desired film thickness on aggregates and surface treatments. They test the stone and sand seal emulsions for demulsibility to insure quick bonding adhesion to and retention of the aggregates. They test sieve to check for large particles that could plug pumps, lines or nozzles on distributors. They test for storage stability and settlement so that the emulsions remain stable in storage and don’t separate. They run distillations and oven evaporations to assure the asphalt content and to obtain residues to test for end-use properties such as penetration, ductility and float. We run other tests to satisfy ourselves that the emulsions meet all of your specifications, perform consistently well during construction, and give the desired field performance.
We manufacture and test emulsions in our lab to continuously improve and develop new formulations, to meet specifications, to make sure the emulsions and aggregates are compatible and for quality control. We stand behind our materials, and it is our relentless laboratory verifications that make this possible.
Cold Mix Designs
Asphalt emulsion mixes are very versatile in the field. They allow economical paving in remote areas and they make winter patching of potholes easy. To give the desired performance, the emulsions must be formulated to fully coat the aggregates without prematurely breaking, or the asphalt will ball up on the fines and not function as an effective binder. Once the aggregates are fully coated, the emulsion must then break, so it forms a water-impermeable film around the aggregates and isn’t washed off. Therefore, when our technologists design cold mixes, the emulsion must be compatible with the aggregate and the break must be controlled. The aggregates must have the volumetric properties to give structural strength on the pavement. Stockpiled patch mixes must remain workable throughout the year. It is our laboratory staff that makes all these things happen. They run the gradations and volumetrics on the project aggregates. They mix the aggregates with emulsions with different levels of emulsifiers and additives, run tests for coating and water sensitivity (stripping), and compact specimens for strength testing. Our cold mix design and quality control testing by dedicated professionals makes sure that you are satisfied with the quality of our cold mix materials and construction.