Abstract: Plastics are man-made materials based on organic polymers. Plastic articles and structures are made from raw materials called plastic compounds, mixtures containing one or more polymers and various ingredients such as lubricants, stabilizers, fillers, colorants, etc. These are incorporated to improve processing or to change the physical, chemical or electrical properties of the end products. According to the way they react to heat, plastic materials may be classified as thermo-plastics and thermosetting plastics. Articles and structures made from thermoplastic compounds can be repeatedly softened by heat and hardened by cooling, and are based on linear or branched polymers. Thermosetting plastic compounds are based on polymers that undergo a chemical reaction during fabrication to form a cross-linked or tridimensional structure that results in a relatively infusible, intractable and insoluble material. Thermosetting materials cannot be reshaped.
Abstract: The joint width should not be less than the minimum required for the sealant, allowing some flexibility in construction tolerances and counting on cyclical movements of structure. Authors discuss estimating of joint movement and installation temperatures. Examples given.
Abstract: This Digest outlines the principles of good drainage practice around buildings to prevent wet basements, frost heaving problems, and the build-up of hydrostatic pressure on basement floors and retaining walls. Good surface drainage can be achieved by proper grading, well planned ditch systems and ensuring culverts are of sufficient size to handle the maximum surface runoff that can be expected at a site. Adequate subsurface drainage can be achieved by careful placement of drainage tile, and the use of suitable filters and permeable backfill material.
Abstract: Polymeric materials have considerably lower thermal stability than metals; most are flammable, but they can be formulated to be fire-resistant. They are good electrical insulators, have much lower modulus than metals, but higher strength-to-weight ratio; and exhibit viscoelastic behaviour, implying time dependence. In contrast with metals, polymeric materials exhibit creep effect, even at room temperature. According to their stress-strain behaviour, they can be divided into four classes: hard and brittle, hard and strong, hard and tough, and soft and tough. Polymers and plastics are generally resistant to alkalis, acids, and water but most are affected by certain organic solvents. Their outdoor weathering resistance varies from excellent to poor but most commercial plastics can now be compounded to show fairly good weathering performance. Chemical, electrical, and physical properties ( including mechanical properties) depend on the nature and amount of the various compounding ingredients.