DCC10032 – ENGINEERING MATERIALS

DCC10032 – ENGINEERING MATERIALS. CHAPTER 1: CONCRETE MATERIALS & MIXTURE.

Concrete Materials and Mixture. Identify the different components of concrete materials. Describe the materials in concrete mixture; cement, fine aggregate, coarse aggregate and water., List the advantages and disadvantages of concrete in the construction industry, List the types of cement, State the properties of cement in concrete mixture; the chemical composition in cement, process of hydration in concrete and the storage method of cement, Describe the properties of aggregates in concrete; classification and sources of the aggregates, criteria of aggregates and function of the aggregates and its relation to the strength of concrete, Discuss the behavior of water in concrete mixture; role of water in concrete mixture and the suitable water quality for concrete mixture. Explain the basic knowledge of concrete mixture. Describe difference types of concrete mixture; prescribed mix, designed mix and nominal mix, Classify the ratio of proportions in concrete mixture, Distinguish the purposes of the following admixture in concrete mixture ; catalyzing substances, retarding substances, water decreasing substance, plasticizing substances, air trapping additive and easy mixing additive. admixture in concrete mixture; Make use of basic knowledge of concrete mixture to classify fresh concrete and hardened concrete. Show the relationship between fresh concrete and the workability of concrete, List the factors influencing workability on fresh concrete; water-cement ratio, aggregate-cement ration, shape and surface texture of aggregate and admixture substance, Explain the test on workability and strength of concrete; slump test, compacting factor test and cube test, Explain the criteria of hard concrete.

Concrete mixture (M20) Fig. 4: Slum value test of M20 grade concrete | Download Scientific Diagram.

te Classification Size Fine Aggregate • Sand and/or crushed stone. • nun. • F.A. content usually by mass or volume of to' aggregate. • Coarse Aggregate • Gravel and crushed stone. • nun. • Typically 9 S and 37.5 mm..

Seven Must-Use Concrete Admixtures (Additives). Types of Admixtures for Concrete - The Concrete Network.

Concrete Foundation - Three Types of Concrete Foundations - The Concrete Network.

ADVANTAGES OF CONCRETE. Low Tensile Strength Economical The material is readily available Malleable (can cast into shape) Durable High Temperature resistance Hardens at ambient temperatures Energy Efficiency in production Low or zero maintenance Do not shrink Less Corrosive.

disADVANTAGES OF CONCRETE. Brittle failure of lime plastered specimen loaded flat. 3.1.3.... | Download Scientific Diagram.

Concrete Materials. CONCRETE MIX DESIGN FINE AGGREGATE ( SAND ) CEMENT COARSE AGGREGATE WATER BLUE METAL ).

Related image. CEMENT. Cement is a type of manufactured goods produced by burning limestone mixture and clay. This substance have two main feature namely adhesion and cohesion. These qualities enable cement act as binder that is good to bind aggregate to form a concrete body that solid and strong. Each bag contains 50kg of cement..

Types of cement. 15+ Types of Cement Used in Modern Construction.

Types of cement. 1. Ordinary Portland Cement (OPC) Ordinary Portland cement is the most widely used type of cement, which is suitable for all general concrete construction. It is the most commonly produced and used type of cement around the world, with annual global production of around 3.8 million cubic meters per year. This cement is suitable for all kinds of concrete construction. 2. Portland Pozzolana Cement (PPC) Portland pozzolana cement is prepared by grinding pozzolanic clinker with Portland cement. It is also produced by adding pozzolana with the addition of gypsum or calcium sulfate or by intimately and uniformly blending Portland cement and fine pozzolana. This cement has a high resistance to various chemical attacks on concrete compared with ordinary portland cement, and thus, it is widely used. It is used in marine structures, sewage works, sewage works, and for laying concrete underwater, such as bridges, piers, dams, and mass concrete works, etc..

Types of cement. 3. Rapid Hardening Cement Rapid hardening cement attains high strength in the early days; it is used in concrete where formworks are removed at an early stage and are similar to ordinary portland cement (OPC). This cement has increased lime content and contains higher c3s content and finer grinding, which gives higher strength development than OPC at an early stage. The strength of rapid hardening cement at the three days is similar to 7 days strength of OPC with the same water-cement ratio. Thus, the advantage of this cement is that formwork can be removed earlier, which increases the rate of construction and decreases the cost of construction by saving formwork cost. Rapid hardening cement is used in prefabricated concrete construction, road works, etc. 4. Quick setting cement The difference between the quick setting cement and rapid hardening cement is that quick-setting cement sets earlier. At the same time, the rate of gain of strength is similar to Ordinary Portland Cement, while quick hardening cement gains strength quickly. Formworks in both cases can be removed earlier. Quick setting cement is used where works is to be completed in very short period and for concreting in static or running water..

Types of cement. 5. Low Heat Cement Low heat cement is produced by maintaining the percentage of tricalcium aluminate below 6% by increasing the proportion of C2S. A small quantity of tricalcium aluminate makes the concrete to produce low heat of hydration. Low heat cement suitable for mass concrete construction like gravity dams, as the low heat of hydration, prevents the cracking of concrete due to heat. This cement has increased power against sulphates and is less reactive and initial setting time is greater than OPC. 6 . White Cement It is prepared from raw materials free from Iron oxide and is a type of ordinary portland cement, which is white. It is costlier and is used for architectural purposes such as precast curtain wall and facing panels, terrazzo surface, etc. and for interior and exterior decorative work like external renderings of buildings, facing slabs, floorings, ornamental concrete products, paths of gardens, swimming pools, etc..

Types of cement. 7. Portland- Blastfurnace Cement (BS 146:1973) It is made by grinding a mixture of OPC (clinker) with selected granulated blast furnace slag. It prevents from chemical reactions. More cheaper than OPC. Moreover, it is sulphate resistance and good for seawater structure. 8. Sulphate Resistant Portland Cement It is a type of Portland Cement in which the amount of tricalcium aluminate (C3A) is restricted to lower than 5% and (2C 3A +C4AF) lower than 25%, which reduces the formation of sulphate salts. The reduction of sulphate salts lowers the possibility of sulphate attack on the concrete. It is darker in colour compare to OPC..

INGREDIENTS FOR CEMENT. Ingredient Percentage (%) Lime 64 Silica 23 Alumina 5 Iron Oxide 3 Magnesia 2 Sulphuric Anhydride 2 Soda and Potash 1.

Name of Compound Usual Abbreviation Reaction Tricalcium Silicate C 3 S Quick Dicalcium Silicate C 2 S Slow Tricalcium Aluminate C 3 A Very Quick Terracalcium Aluminoferrite C 3 AF Not Very Important.

Concrete: Scientific Principles.

PRODUCTION PROCESS Ore.

STORAGE METHOD OF CEMENT. Cement storage – usage & guidelines as per the CODAL provisions.

STORAGE METHOD OF CEMENT Silo. (3.

AGGREGATES. Fine Aggregate: Fine aggregate size does not exceed 5mm. It available from mine sand, quarry or river. Function of fine aggregate : Filling empty spaces in concrete mixture to strengthen the concrete mixture. To prevent steel reinforcement from rusty. As bond which ensures compaction of mixture..

AGGREGATES. wiseGE. Coarse Aggregate: The size among 5mm to 50 mm. Usually is acquired from the quarry. Function of coarse aggregate : A s filler to concrete volume. As material that increase concrete strength. Giving concrete resilience and hold shrinkage. Aggregate content is 60-80% from concrete volume..

Image result for water. WATER. Function of water in concrete mixture: Water spread cement so that each stone item covered tightly. Water gives convenience work in concrete mixture. Water is chemical reaction agent in cement to tie all aggregate in concrete mixture..

Image result for river water. WATER. Types of water used to mix concrete: i. T ap water. ii. Water free minerals and organic materials such as salt, alkali iii. Other water sources - river water, rain water or drainage..

ADMIXTURE. Admixtures are defined as materials other than aggregate (fine and coarse), water, fibre and cement, which are added into concrete mix immediately before or during mixing..

ADMIXTURE. Chemical admixtures can modify the setting and hardening characteristic of cement paste by influencing the rate of cement hydration. Water-reducing admixture can plasticize fresh concrete mixtures by reducing surface tension of water. Air-entraining admixtures can improve the durability of concrete. Mineral admixtures such as pozzolan (materials containing reactive silica) can reduce thermal cracking..

ADMIXTURE. Types of Admixture Uses Accelarators ( Bahan Pencepat ) - (Catalyzing substance) Quick hardening process (hydration / hardening) concrete. Retarders ( Bahan Pelambat ) - (Retarding substance) Delaying harden concrete process. Water reducers ( Bahan Pengurang air) - (Water decreasing substance) Reduce water content in concrete mixture. Air entrainment ( Bahan Tambah Perangkap Udara) - (Air trapping additive) Resist to frost . Creating air bubble. Plasticizer ( Bahan Tambah Pemudah adun ) (Easy mixing additive) To ease concrete spread..

CONCRETE MIXTURE. Ill:l II.

Concrete Mixing Aspects to consider:. Safety Concrete mixing ratios Mixing the fundamental ingredients Sunlight and curing speed..

CONCRETE MIXTURE RATIO. Mix Ratio : 1:2:4 1 = Cement 2 = Fine Aggregate 4 = Coarse Aggregate.

CONCRETE RATION AND PURPOSES. How to calculate materials for different-ratio concrete - Best online Engineering resource! | Concrete mix design, Concrete mix ratio, Concrete mixes.

C10 Used for: Patio slabs, pathways and non-structural work Type: Domestic & commercial use C15 Used for: Pavement kerbs and floor blinding Type: Domestic & Commercial C20 Used for: Domestic floors and foundations (where the weight of structure will be lighter). Also good for workshop bases, garages, driveways and internal floor slabs. Type: Domestic C25 Used for: Construction in all areas. Multi-purpose concrete mix, usually used for foundations. Type: Domestic & Commercial C30 Used for: Pathways and roadways (this is the lowest grade concrete mix that can be used for this purpose). More durable than the grades that have come before, and thus is much more weather-resistant and can take heavy road traffic. Type: Commercial C35 Used for: Commercial structures. This heavy concrete mix is usually used for creating external walls and slabs, as well as for structural piling. Type: Commercial C40 Used for: Commercial construction sites, creating foundations and beams for structural support and roads. The most durable in this list, C40 can withstand chemical corrosion also, so is frequently used on farms where slurry could corrode structures, or in septic tanks. Type: Commercial.

TYPE OF CONCRETE MIXTURE. Prescribed Mix Designed Mix Nominal Mix.

Prescribed Mix. Based on weight Concrete mix is decided by engineer. Compressive strength is commonly achieved more than the design of grade of concrete..

Designed mix. Based on volume of concrete. Concrete mix is decided by the contractor. Best practice of trial mix is determine..

Nominal Mix. Base on volume of concrete. Compressive strength is commonly achieved less than the design of grade of concrete. Design by engineer. Design by weight : V = M/D V=volumn, M=mass, D=density.

CONCRETE MIX QUALITY. Concrete mix quality depend on: The mixture materials quality. The mixture mixing ratio. Ratio which normally used (cement : sand : aggregate) is: 1:2:4, 1:3:6, 1:5:10, according to place and purpose. Mixing method and transport. Mould quality used. Compression after being placed in mould. Preservation method..

WORKABILITY. Workability is often defined as the amount of mechanical work required for full compaction of the concrete without segregation..

Factors influence workability. Water – Cement Ratio 01 Aggregate- Cement Ratio 02 Shape and Surface Texture of Aggregate 03 Admixture Substances 04.

Water – Cement Ratio. Water used to produce concrete mixture that like plastic and easy being worked. If water used more than limit, strength and concrete density will decline. If water used too less, the concrete difficult to be being worked and process imperfect hydration..

Water – Cement Ratio. If lower water-cement ratio, concrete strength will increase, less workability and make casting works and concrete compaction is harder. a) water-cement ratio = Concrete Strength = Workability b) water-cement ratio = Concrete strength = Workability Calculate based on weight or volume..

Table 1. Strength versus W/CM Ratio (Ref.1) Compressive Strength (28 days, psi) W/CM Ratio Non-air-entrained Concrete Air-entrained Concrete 7,000 0.33 - 6,000 0.41 0.32 5,000 0.48 0.40 4,000 0.57 0.48 3,000 0.68 0.59 2,000 0.82 0.74.

Calculation. Example : If 27 liter of water use to mixing one bag of cement (50kg), the water-cement ratio is ; 27 x 1 = 0.54 50.

Aggregate - Cement Ratio. Coarse and fine aggregate should comprise from various size to produce void that is minimum. 01 Cement should be sufficient to fill void in sand. Mixture of sand and cement also should be sufficient to close void in coarse aggregate. 02 excessiveCement and sand are needed to produce mixture with workability that is high. 03.

Shape and Surface Texture of Aggregate. Coarse aggregate with smooth surface can give good workability but low in bond strength. Example: Smooth aggregate = strength of bond Rough aggregate = strength of bond Meanwhile aggregate with rough surface produce low workability but good in strength bond between aggregate and cement ..

TYPES OF WORKABILITY TEST. 1. Slump test 2. Compacting Factor Test 3. Ve-be Consistometer 4. Cube Test.

Slump Test.

Compacting Factor Test. Hopper Same dimensions lm•et Hopper 9mm dia 3mmm high.