Students work in pairs to research how changing the ratios of cement, water and aggregates affect concrete. They must record their results and draw appropriate conclusions.
Understanding concrete’s chemistry and behavior will help you avoid problems during installation or at least mitigate them, and this guide is here to assist with that goal.
How it is made
Concrete slabs Melbourne is one of the world’s most commonly used building materials, familiar to most homeowners through DIY projects such as setting fence posts or basketball hoops or laying patio slabs. Yet many aspects of working with concrete remain poorly understood – this guide hopes to fill any knowledge gaps that make working with it more complex than necessary.
Concrete is a composite material composed of three ingredients: water, aggregate (typically sand or gravel) and Portland cement. The ratios can differ depending on its final use; when mixed together they undergo chemical reaction known as hydration which provides strength to concrete.
Properties
Concrete is an adaptable material that can be tailored to a variety of applications ranging from residential foundations to skyscrapers and massive hydroelectric dams. To meet specific requirements, its basic recipe can be modified accordingly to produce desired results.
Concrete’s cement component bonds together the aggregate particles, then hardens over time through hydration to form an indestructible rock-like mass. Hydration gives concrete its remarkable properties – plastic and workable when freshly mixed but strong and durable when set hardened.
Enhancing the properties of concrete can also be done using additional materials such as fly ash, ground granulated blast furnace slag (GGBFS), recycled glass or waste vehicle tires; thus helping reduce industrial waste production while making concrete more environmentally friendly.
Mixing
Mixing concrete can be accomplished either manually, by machine on-site, or pre-mixed and delivered (known as ready mix). Mixing by hand is usually reserved for smaller do-it-yourself home projects.
Water is key in mixing concrete. Too little and the concrete won’t hydrate; too much and it becomes weak and soupy.
When mixing concrete by hand, using a wheelbarrow or large bucket is the easiest and cleanest way. Additionally, waterproof gloves and eye protection should always be worn as cement can burn skin and eyes if it comes into contact. A dust mask is recommended to prevent inhaling cement dust.
Placement
Concrete installations can take place in various structures and surfaces, each installation presenting its own challenges. This guide offers information regarding pre-installation, placement and post-installation for residential and commercial concrete installations.
This book, the third of a popular series on decorative concrete, provides contractors with comprehensive instructions for rejuvenating existing floors, exterior flatwork and walls using decorative concrete overlays. This comprehensive manual covers application techniques, material estimation and surface preparation/crack repair procedures in detail as well as providing in-depth coverage on stampable/self-leveling overlays.
ACI Technical Committees share knowledge by publishing consensus-based guidance in the form of guides, reports and Tech Notes. These documents offer committee recommendations regarding analysis, design, specification selection evaluation testing construction repair of concrete materials or structures. ACI members enjoy free digital access to ACI’s entire library of guides reports and Tech Notes.
Finishing
An expertly finished concrete surface not only looks better, but is more resistant to damage as well. The finishing process involves smoothing and texturing freshly poured concrete; it requires skill learned over years of practice; trained experts can “time” their finishing operations perfectly to transform wet concrete into polished masterpieces.
Achieve a smooth finish requires adequate formwork, release agent, and concrete mix maturation to create a striking surface with smooth arises and free of major honeycombing issues.
Once the concrete has set slightly post-floating, it’s time to use a trowel. For optimal results, work in small circles for best results; an edging tool may also come in handy to give rounded corners to the concrete surface.