Twining has dedicated a segment of our resources to materials engineering and the research, development and engineering of concrete and cementitious materials and alternative cements.
For the past five years we have been supporting collaborative efforts to improve the sustainability of concrete construction and to reduce its environmental impact. Applied research performed by our firm for state agencies and private firms includes:
- Evaluation of the addition of limestone to portland cement and its influence on the performance of concrete
- Development, evaluation and implementation of concrete mixtures containing high volumes of industrial by-products as supplementary cementitious materials
- Development, evaluation and implementation of concrete mixtures with recycled concrete aggregates
Results of our collaborative research and development work with limestone have allowed Caltrans to approve the addition of limestone to portland cements used for the construction of pavements and transportation structures. This has enabled a savings of up to 5% of clinker and reduced carbon dioxide emissions caused by portland cement production.
The results of research and development performed with Twining’s participation are currently being used by Caltrans to revise standard specifications for proportioning concrete for pavements and elements of transportation infrastructure. Also based on the data developed by Twining, the Division of the State Architect has approved substitution of up to 35% of portland cement with Class F fly ash for specific projects constructed by Los Angeles Community College District.
Our acquired experience in the engineering of cement based composites containing high volumes of unprocessed and processed supplementary cementitious products has also been applied to the development of advanced building materials and construction materials with special properties. Some of the examples are:
- High strength cementitious-based spray-applied mortar for multi-layered external wall panels with Styrofoam insulation
- Impervious and pervious cellular grouts, controlled low strength flowable fills and concretes
- Architectural polymer modified dry mixtures for construction of artificial rock and manmade elements of authentic landscapes
An additional example of materials we have engineered for special applications are compositions for the rehabilitation of secondary water treatment facilities and sewer conveying systems. Low permeability repair mixtures formulated and tested with the participation of Twining Infrastructure were, for example, used for rehabilitation of secondary water treatment facilities in Carson, California.
Twining Infrastructure works in close collaboration with companies developing new products for the building materials industry. Thus, we can keep our clients informed of innovations and help them apply these innovations in a way that improves technical results and lowers cost.
Twining Infrastructure sets the standard for innovation and experience in the field of concrete technology. Our services encompass:
- Certification of concrete batch plants and transit mix trucks in accordance with NRMCA requirements
- Calibration of concrete volumetric mixers
- Qualification of concrete producing units for uniformity
- Evaluation of concrete materials including portland cement, supplementary cementitious materials, aggregates, and chemical admixtures
- Development and evaluation of production mixtures
- Field consultations and engineering support in production and application of cast-in-place and precast concrete
- Quality control and quality assurance of concrete production and construction including development of quality control manuals and procedures
- Forensic investigation of concrete structures and pavements
- Development of remedial measures for repair of concrete structures
- Training for our clients’ technical personnel on various aspects of concrete materials engineering and technology
Versatile engineering, laboratory and field capabilities make Twining Infrastructure your single point of contact for concrete technologies and construction. We are capable of evaluating concrete for the most sophisticated requirements of various specifications, including all types of testing formechanical properties, moisture-related volume changes, cracking resistance, rapid chloride permeability, coefficient of chloride diffusion, content of chlorides, sulfates, pH, and others. Our laboratories are equipped with mixers allowing the simulated production of ready-mixed (transit-mixed) and precast concrete, foam generators for producing cellular concrete, grout and mortar mixers. For simulating precast concrete production methods we use steam curing and dry curing heat treatment chambers and vibration tables.
Twining Infrastructure has contributed significantly to the development of concrete production and construction in California. Prominent concrete projects we’ve collaborated on include underground tunnels for the Metro Red Line, San Diego ocean outfall, Disney’s California Adventure, Walt Disney Concert Hall, The Californian and other highrise buildings utilizing high strength concrete, Runway 25L at Los Angeles International Airport, replacement pavements on highways and freeways throughout the state, and many others.
Our firm is evaluated and accredited by the Cement and Concrete Reference Laboratory (CCRL), American Association of State Highway and Transportation Officials, International Accreditation Service (IAS), State of California Department of Transportation (Caltrans), the Army Corps of Engineers andmany local agencies. Their intensive evaluation of every aspect of our testing procedures for cement, fly ash, aggregates and concrete assures clients of the integrity and accuracy of our test results.
Concrete For Pavements And Infrastructure
Twining Infrastructure is the premiere provider of services related to concrete for pavements and infrastructure construction. From preconstruction evaluation of concrete making materials and the development of concrete mix designs, through full support during the production and application of the mixes, our experience and technical expertise allow us to meet the needs of even the most demanding projects. The comprehensive nature of our firm– top technical experts who consult on the design and use of concrete materials to field personnel who oversee their ultimate application – ensures that we take a big picture approach and have a thorough understanding of what it takes to make a project successful.
Twining Infrastructure has a record of developing and delivering innovative concrete mixtures to the construction industry. Our experience encompasses all types ofmixtures used for concrete construction in California. Examples include:
- Mixes for various types of concrete pavements including freeways, bridge decks, and airfields
- Pavement mixes for fast-track roadway construction and rehabilitation
- Rapid strength concrete mixtures for approach slabs
- Lean concrete base and econocrete mixes for roadways and airfields with recycled and natural aggregates, both regular and rapid strength
- Pervious concrete mixtures for roadways and parking lots
- Pervious and regular cellular concrete mixtures for bridge approaches, flowable fills, etc.
- Mixes with high volumes of supplementary cementitious materials such as fly ash and ground granulated blast furnace slag, improving sustainability of construction and reducing carbon dioxide emission
- Mixes with recycled aggregates
- High-performance concrete mixtures for bridge decks and other structural applications
- Low heat of hydration mass concrete for dams, massive foundations, etc.
- Concrete mixtures with controlled drying shrinkage
- Self-consolidating concrete
- Concrete with improved corrosion resistivity, i.e. for secondary water treatment facilities
In addition to developing concrete mixtures, our firm has the ability to evaluate the concrete, to create all of the backup data necessary to obtain industry approval, to provide technical support during the production and application of the concrete and to provide quality control and quality assurance testing and inspection.
Twining Infrastructure is frequently sought out by companies developing new concrete technologies because they hear from authorities and others in the industry that Twining is simply the best at evaluating new materials and methods. Technology transfer and forensic investigation round out our list of concrete services.
One example of our comprehensive approach to providing services is fast track rehabilitation of concrete pavements. Twining Infrastructure has participated in the development, evaluation and implementation of various types of rapid strength concrete for both repair and new construction of highways and airfields. We have developed testing procedures and mobile laboratories for field testing of rapid strength concrete, created the first Just-in-Time Training seminar on rapid strength concretes and their use for pavement rehabilitation and new construction and provided more than one hundred seminars to the construction industry. As a quality control and quality assurance agency Twining has participated in more than 300 pavement rehabilitation and new construction projects utilizing rapid strength concrete.
The materials engineering department is led by Dr. Boris Stein, who has more than thirty years of experience and is well known in the world of concrete. He holds fifteen patents and certificates on inventions related to concrete technology. Dr. Stein has directed technical services for hundreds of concrete infrastructure projects including pavements, secondary water treatment facilities, utility and transportation tunnels, bridge investigations and others.