Classroom Teaching Aids And Laboratory Experimentation To Engage Students In Materials Learning

Most civil engineering programs require one course in materials and materials testing. These courses are designed to provide students with general knowledge of the production, properties, and behavior of common structural materials. Emphasis is often placed on the three predominately used materials: concrete, steel, and wood. This paper presents teaching aids and laboratory experiments that can be used as an effective method of introducing material properties and behavior to students. The authors have identified several analogies, in-class demonstrations, visual aids, and laboratory experiments that enhance the learning of structural materials. The “Hamburger Helper” analogy can be used to describe aggregate’s function as economical filler in concrete as noodles (aggregates) are considerably cheaper than hamburger meat (cement) and can be used to produce a larger meal (concrete mixture) at a reduced cost. Cement hydration is often a difficult topic for students to understand. The reaction between water and cement can be demonstrated using a candy, the “Atomic Fireball.” The heat liberation curve for cement hydration resembles the heat given off by an Atomic Fireball. The stress-strain curve for steel can be described as “Traffic Gridlock on an Interstate.” The initial portion of the curve resembles slow moving traffic that produces large amounts of stress for drivers. This is followed by a point on the curve or location on the interstate when traffic speed increases resulting in decreased stress and much greater strain. This comparison continues through strain hardening until failure or the drivers reach their destination. Straws are an effective method of illustrating the structure of wood. Wood is composed of hollow tube-like cells that resemble a group of drinking straws. Laboratory experiments that examine the effects of water-to-cement ratio and curing environment on concrete compressive strength reinforce topics discussed in class lectures. Teaching aids and laboratory experiments are an effective method of demonstrating important concepts. The methods discussed in this paper have shown to engage students in the learning of structural materials.