• Cement Fineness| Concrete Construction Magazine

     · 9. Both airentrained and non airentrained concrete containing 100 percent reactive aggregate are detrimentally affected by increased expansion at all ages by increases in the fineness of a highalkali cement. 10. A very coarse cement under some conditions can cause a serious bleeding problem on some construction projects. 11.

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  • (PDF) COMPRESSIVE STRENGTH OF CONCRETE USING NATURAL AGGREGATES (GRAVEL ...

    Generally, cement and coarse aggregates are factory made products and their quality and standards can be easily controlled and maintained. Water used for mixing of concrete is usually tap water. The fine aggregates or sand used is usually obtained from natural sources particularly river beds or river banks.

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  • The mechanical and physical properties of concrete containing ...

     · These samples were cured under water curing condition for 7, 28 and 56 days before testing. Eight types of mixtures were cast based on percentage (25%, 50%) of polystyrene beads replacement for control samples and (25%, 50%) of polystyrene beads by different ratio 10%, 15%, and 20% replacement of palm oil fuel ash, respectively.

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  • CONCRETE WITH RECYCLED AGGREGATES

    2: Specifiion for constituent materials and concrete" establishes the use of recycled concrete aggregates in concrete. The aggregates are classified into two groups: RCA (recycled concrete aggregates) and RA (recycled aggregates). The difference between these two types is related to the composition.

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  • Aggregates

    Unitweight measures the volume that graded aggregate and the voids between them will occupy in concrete. The void content between particles affects the amount of cement paste required for the mix. Angular aggregates increase the void content. Larger sizes of wellgraded aggregate and improved grading decrease the void content.

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  • PRODUCTS | Blue Planet Systems

    As a manufactured aggregate it is possible to control the physical properties meaning the it can be lightweight or normal weight depending on the requirements of the concrete. Both coarse and fine aggregate can be produced using the Blue Planet process. Every tonne of Blue Planet aggregate contains 440kg or 970 lb of CO2 Upcycled Aggregate

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  • Mechanical Properties of Aggregate

     · Raise the hammer to a certain height (about 15 inches above the top surface of cup containing aggregates) and allow it to fall freely and exert an impact load on the sample. Repeat this process for 15 times. Remove the material from cup and pass it through sieve. Note the fraction passing the sieve as .

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  • TopCrete Exposed Aggregate Overlay

    Freedom to Choose. Provided as drymix form containing the binder and the decorative aggregates, TopCrete 700 is installed over existing concrete in thicknesses ranging from 68 mm to 30 mm depending on the aggregates size, but most commonly in 1015 mm. Thus designers and clients are free to choose from a wide variety of binder colors and ...

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  • Iron Sulfides in Concrete | RJ Lee Group, Inc. (RJLG)

     · Pyrite is the most stable iron sulfide mineral, but can still oxidize near the surface of concrete and stucco, leading to unsightly staining and popouts. In goodquality dense concrete, aggregate containing small amounts of pyrite can be successfully used without affecting durability of the structure. Figure 2. Cracked concrete foundation wall.

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  • Aggregates

    Aggregates. Aggregates are inert granular materials such as sand, gravel, or crushed stone that, along with water and portland cement, are an essential ingredient in concrete. For a good concrete mix, aggregates need to be clean, hard, strong particles free of absorbed chemicals or coatings of clay and other fine materials that could cause the ...

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  • Aggregates for Concrete

    For adequate consolidation of concrete, the desirable amount of air, water, cement, and fine aggregate (that is, the mortar fraction) should be about 50% to 65% by absolute volume (45% to 60% by mass). Rounded aggre gate, such as gravel, requires slightly lower values, while crushed aggregate requires slightly higher values.

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  • Alkali Content of Concrete Mix Water and Aggregates

    control the amount of alkali added to the concrete when it is mixed. For Normal Concrete, as defined by NZS 3104:2003, the concrete producer is required to certify that the total alkali in the concrete, contributed by all constituents of the mix, does not exceed /m3. Control of alkali content is one of several approaches that may be taken for

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  • INNOVATIVE METHODS TO MITIGATE ALKALISILICA REACTION IN CONCRETE .

    effective methods to mitigate ASR in concrete containing recycled glass, the research objectives of this PhD study are: 1 To understand the mechanisms through which fly ash controls ASR in accelerated mortar bar test (AMBT). 2 To investigate the .

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  • Concrete Demolition: Aggregate Technologies, Inc.

    December 2015 Concrete Openings Damaged dolphin Port of Houston February 2015 Construction Executive "Mickey" Leland Federal Building renovation project . March/April 2015 Pile Buck Magazine Underwater wire sawing and core drilling

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  • Strength Properties of HighStrength Concrete Containing Coal .

     · In addition to the control concrete mixture, for each mixture, CBA replaced 25, 50, 75, and of the natural fine aggregates by volume in the concrete. The unit contents of cement and natural coarse aggregates were fixed at kg/m 3 and kg/m 3, respectively, when fabriing all the mixtures.

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  • EFFECTS OF AGGREGATE TYPE, SIZE, AND CONTENT ON CONCRETE .

    strength concrete containing basalt is controlled by the strength of the rock and the ... There is much controversy concerning the effects of coarse aggregate size on concrete, principally about the effects on fracture energy. Some research (Strange .

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  • Recent Trends and Advances in Recycled Concrete Aggregate

     · The use of recycled aggregate is an effective solution to the problem of having too much waste while still maintaining satisfactory concrete quality. Indeed, if quality assurance systems for achieving suitable product properties are appropriately defined and controlled, and additives are the result of ongoing research and development processes ...

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  • STRUCTURAL BEHAVIOUR OF REINFORCED CONCRETE BEAMS CONTAINING .

    cement content and the W/C ratio were kept constant at 320 kg/m3 and, respectively. The control mixture had a proportion of 1 (cement): 6 (natural aggregate). Each mix comprised six beams; the first two beams containing 2 tension reinforcement steel bars only without shear reinforcement (without stirrups) (Type 1), two beams containing

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  • Performance of Rigid Pavements Containing Recycled Concrete Aggregates

    pavements containing recycled concrete aggregate (RCA). Success has been attributed in part to the minimization of old mortar content in the RCA during recycling processes, thereby controlling the total mortar content of the new portland cement concrete (PCC) mixture, or to the achievement of higherthanexpected compressive strengths

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  • Structural Behavior of Reinforced Concrete Slabs Containing Fine .

     · The aim of this research is to investigate the effect of replacing 75% of sand volume with polyvinyl chloride (PVC) fine waste aggregates on the performance of reinforced concrete slabs. Different thicknesses of the concrete layer (0%, 25%, 50%, and of slab thickness) containing PVC fine waste aggregates are investigated.

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  • Heat resistant concrete

    The effects of fire on concrete are greatly influenced by the type of coarse aggregate used. Concrete containing carbonate aggregates (including limestone and dolomite) and lightweight aggregates (either naturally occurring or manufactured by expanding shale, clay, or slag) retain most of their compressive strength up to 1200 degrees F.

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