Author name: prajapatiseema390

Scope  This Part of this British Standard describes a method for determining the density of compacted fresh concrete. The method applies to plain and air-entrained concrete, made with lightweight, normal weight or heavy aggregates having a nominal maximum size of 40 mm or less, but not to aerated concrete or very stiff concrete which cannot …

BS 1881-107 Part 107: Method for determination of density of compacted fresh concrete Read More »

Scope  This Part of this British Standard describes two methods for determination of air content of compacted fresh concrete, made with normal weight or relatively dense aggregate having a nominal maximum size of 40 mm or less.  Neither of the methods is applicable to aerated concrete, very stiff concrete which cannot be compacted by vibration …

BS 1881-106 : Part 106: Methods for determination of air content of fresh concrete Read More »

Scope This Part of this British Standard describes a method for determining of Vibe time of concrete of very low to low workability.  The method applies to plain and air-entrained concrete made with lightweight, normal weight or heavy aggregates having a nominal maximum size of 40 mm or less but not to aerated concrete, no-fines …

BS 1881 -104 Part 104: Method for determination of Vebe time Read More »

Scope  This Part of BS 1881 describes the method for determining the compacting factor of concrete of low, medium and high workability. The method applies to plain and air-entrained concrete, made with lightweight, normal weight or heavy aggregates having a nominal maximum size of 40 mm or less but not to aerated concrete,   no-fines concrete …

BS 1881-103: Part 103: Method for determination of compacting factor Read More »

Scope This Part of this British Standard describes a method for determining of slump of cohesive concrete of medium to high workability.  The method applies to plain and air-entrained concrete, made with lightweight, normal weight or heavy aggregates having a nominal maximum size of 40 mm or less but not to aerated concrete and no-fines …

BS 1881-102 Testing concrete — Part 102: Method for determination of slump Read More »

Scope  This Part of this British Standard describes the method for making and curing 150 mm test cubes of fresh no-fines concrete made with aggregate having a nominal maximum size of 40 mm or less. Procedure 6.1 Making test cubes.  Fit the extension piece to the mould and, using the scoop, carefully place a layer …

BS 1881-11 Testing concrete — Part 113: Method for making and curing no-fines test cubes Read More »

Scope This Part of this British Standard describes methods to be used on site for obtaining from a batch of fresh concrete representative samples of the quantity required for carrying out the tests and making test specimens in accordance with other Parts of this British Standard together with a procedure for determining sampling errors using …

BS 1881-101 Testing concrete — Part 101: Method of sampling fresh concrete on site Read More »

Rust strain in concrete Cause Pyrites in aggregates Rain streaking from unprotected steel Rubbish in formwork  End of wire ties turned out Prevention Avoid contaminated aggregates  Protect exposed steel clean forms thoroughly Turn ends of ties inwards Remedy Clean with dilute acid or sodium citrate/sodium dithionite. Apply surface coating

 Color variation in Concrete Cause  Variation in mix proportion  Curing condition Materials Characteristics of form face vibration release agent leakage of water from formwork Prevention  Ensure uniformity of all relevant factor  Prevent leakage from formwork Remedy Apply surface coating 

Blow holes in form faces of concrete Cause Air and water are trapped against formwork. Inadequate compaction  Unsuitable mix design unsuitable release agent  Prevention  Improve vibration change mix design use the appropriate release agent use absorbent formwork Remedy Fill with polymer modified fine mortar