Introduction to Concrete Design and Control of Concrete Mixtures CHAPTER 1 Design and Control of Concrete Mixtures, 16th edition, Chapter 1 – Introduction to Concrete

Overview Industry Trends The Beginning of an Industry Sustainable Development Essentials of Quality Concrete This module covers the trends of the concrete industry, from the production of cement to concrete applications.

What is Concrete? Cement Water Aggregate Supplementary Cementing Materials Chemical Admixtures Concrete components: cement, water, coarse aggregate, fine aggregate, supplementary cementing materials (SCMs), such as fly ash or slag cement, and chemical admixtures.

Industry Trends Concrete is the world’s most widely used construction material. About four tons of concrete are produced per person per year world wide. About 1.7 tons are produced per person in the United States.

Industry Trends About 230 million cubic meters or 300 million cubic yards of ready mixed concrete are used in the United States each year. Concrete is used as a building material for many applications. These include highways, streets, parking lots, parking garages, bridges, high-rise buildings, dams, homes, floors, sidewalks, and driveways.

Cement Industry 91 operating cement plants in 33 states in the U.S. 59% of U.S. capacity held by top 5 companies Cement production is geographically dispersed with 91 plants in 33 states. The top five companies operate 59% of the clinker capacity.

Cement Storage and Shipment About 97% of cement is shipped to customers by truck. Other distribution modes include rail, barge, and bags.

Cement Consumption 86.5 MMT consumed in 2014 2/3 of consumption between May and October 86.5 million metric tons, or 95 million tons, of cement were consumed in the United States in 2014. Nearly two-thirds of cement consumption occurs between May and October, closely correlating with the construction season.

Cement Consumption in U.S. 68.8% of cement consumption is readily-mixed concrete The pie chart shows cement consumption in the United States by category. 68.8% of cement consumption is ready-mixed concrete. (PCA 2015)

Markets and Application for Concrete Apparent use of portland cement by market (PCA 2015) (PCA 2015)

Primary Markets Pavements Concrete pavements generally provide the longest life, least maintenance, and lowest life-cycle cost of all alternatives.

Primary Markets Bridges More than 70% of bridges throughout the U.S. are constructed of concrete. Prefabricated concrete systems is a popular method to accelerate bridge construction. High-performance concrete (HPC) is often used in bridge applications.

Primary Markets High-Rise Buildings Concrete is the material of choice for high-rise buildings. Reinforced concrete provides inherent stiffness, mass, and ductility.

Primary Markets Low-Rise Buildings Almost more than half of all low-rise buildings in the United States are constructed from concrete. Concrete is durable, has excellent acoustic properties, fire resistance, and ease of construction. It is the most economical choice as load bearing walls eliminate the need to erect separate structural systems.

The Beginning of an Industry The earliest forms of concrete can be traced back to around 7000 BC, which was used in the construction of a road in Galilee, Israel. The terms concrete and pozzolan come from Roman roots. Concrete is derived from the Latin word “concretus”- meaning grown together or compounded. The term pozzolan comes from a volcanic ash mined at the village Pozzuoli, Italy. The Coliseum in Rome, completed in 80 AD, was constructed of concrete. Much of it still stands today.

The following is a timeline of concrete milestones The following is a timeline of concrete milestones. The related references are accessible in the PCA Library.

PCA celebrates its centennial in 2016, marking 100 years of contributions to the cement and concrete industry.

Turning Point 18th century – John Smeaton Use of hydraulic cement versus Non-hydraulic cement In the 18th century, John Smeaton discovered that an impure, soft limestone containing clay minerals made the best hydraulic cement. He used this cement to construct a new foundation for the Eddystone Lighthouse off the coast of Plymouth, England.

Joseph Aspdin Patented portland cement in 1824 Joseph Aspdin, an English mason, obtained a patent in 1824 for portland cement. The name came from the resemblance to limestone quarried from the Isle of Portland, which had been used as a premier building stone since Roman times.

Sustainable Development Concrete is the basis of much of civilization’s infrastructure and much of its physical development. Twice as much concrete is used throughout the world than all other building materials combined. It is a fundamental building material to municipal infrastructure, transportation infrastructure, office buildings, and homes

Essentials of Quality Concrete Suitable Materials Water-Cementitious Materials Ratio Design-Workmanship-Environment The performance of concrete is related to workmanship, mix proportions, material characteristics, and adequacy of curing.

Suitable Materials Concrete constituents include cement, water, and coarse and fine aggregates. The range in proportions of materials used in concrete varies.

Suitable Materials Cross section of hardened concrete made with (left) rounded siliceous gravel and (right) crushed limestone. Cement and water paste completely coats each aggregate particle and fills all spaces between particles.

Water-Cementitious Materials Ratio Ten cement-paste cylinders with water-cement ratios from 0.25 to 0.70. The band indicates that each cylinder contains the same amount of cement. Increased water dilutes the effect of the cement paste, increasing volume, reducing density, and lowering strength. Advantages of optimal water content : Increased compressive and flexural strength Lower permeability and increased water tightness Increased durability and resistance to weathering Better bond between concrete and reinforcement Less volume change from wetting and drying

Summary Industry Trends The Beginning of an Industry Sustainable Developments Essentials of Quality

?