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Welcome to the world of concrete pumping! Learn about ready-mixed concrete, batching plants, quality control methods, and how admixtures can enhance concrete performance. Explore different types of concrete mixes, environmental considerations, and the role of pumps in constructing tall buildings.
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Concrete Required Concrete needed (m3) Time / Months
What is Ready Mixed Concrete? It is concrete that is delivered to site in a fresh, liquid state from a remote batching plant upon order.
Types of Ready-Mixed Concrete • Dry Mix • Wet Mix • Temperature controlled Concrete • Produced in accordance with SS289
How is it done? • Overview of a Batching Plant(BP) • Materials- Aggregates, Sand, Cement and Water are weighted.
Raw materials Water • Aggregates, sand on conveyor belt into the mixer
Advantages • Hassle-free, Fast • Reliability • Quality control is ensured • Less labour required • Space saving on site • Able to meet fluctuating demand • Design Mix is possible
Disadvantage • Cost • 24 hours is needed for an order
Quality Control?? • Slump test • Cube strength test • Aggregate test • Temperature Test • SS 78
Environment Friendly?? • ISO 14001 certified • Recycled water • Cement dust filter
CRITERIA • Well-bond constituent materials • Facilitates the radial movement of sufficient grout along pipeline • Ablility to deform
IF NOT…. • Segregation • Bleeding/Dewatering • Lumpiness
ADMIXTURES - IMPROVING PERFORMANCE -
WHY ADMIXTURES? • Increase workability of concrete 2. To produce specific requirements for the mix, e.g. durability & strength 3. Special Conditions
REFRESHING ON SOME TERMS.... W/C ratio Slump test Workability
TYPES OF ADMIXTURES a) water-reducing admixtures b) retarders and accelerators c) water-thickening admixtures d) air-entraining admixtures e) others
WATER-REDUCING ADMIXTURES What is it? • Plasticiser, SuperPlasticizers, • (SuperFluidizers, SuperFluidifiers, Super Water-Reducers or High Range Water-Reducers) • - Lower water mix requirement • - Amount of water reduction achievable depends on dosage and initial slump Comments • - Difficulties can arise if there is any significant vertical length of pipeline. • Plasticizers should not be used in concrete mixes with high voids content which are prone to segregation
Retarders & Accelerators What is it? Retarders -delay the setting of concrete-offset the effects of high temperatures, long distance pumping & cold joint prevention.- effective use in slip formwork • Accelerators • increase the rate of hydration-shorten the setting time -increase the rate of hardening or strength development. Comment -concrete with accelerator will set more quickly and impacts on schedule -Combining retarder in the bottom half of a thick slab and normal concrete in the top half
The rest… ..not suitable for Singapore (due to climate)
Water-thickening agents What is it? • More cohesive and higher viscosity • Used on leaner mixes • “water-wrapping-aggregate” effect Comments - Used in any mix to provide lubrication and reduce friction.
Air-entraining agents What is it? • Bubbles created • Alters the properties of concrete both in its plastic and hardened state. • Plastic = reduce both water and fine aggregates contents • Hardened = Gives hydraulic relief to any water freezing effect Comments • -Limited the amount of air. • Escape of air • Adding a plasticizer, if there is a concern of over dosage
Other types of admixtures • Pulverized Fly Ash (PFA) • Microsilica • Steel, glass fibre and polypropylene fibres
Thank You for Your Attention Presented by Hing Kai Sin ADD Marketing
Concrete Delivered (m3/hr) Height / m3
