Diary of a Civil Engineer

🔹 What is Slump Cone Test? Slump Cone Test is a simple field test used to measure the workability and consistency of fresh concrete. Workability means how easily concrete can be mixed, placed, compacted, and finished without segregation or bleeding.   🔹 Apparatus Required Slump Cone → Height 300 mm, Top dia 100 mm, Bottom dia 200 mm Tamping Rod → 16 mm dia, 600 mm long, rounded ends Steel Base Plate (non-absorbent) Measuring Scale Fresh Concrete Sample 🔹 Test Procedure (Step by Step) Place the slump cone on a clean, level steel plate. Fill the cone with fresh concrete in 3 equal layers . Compact each layer with 25 strokes of tamping rod. Strike off extra concrete from the top surface. Carefully lift the cone vertically in 5–10 seconds without disturbing concrete. Measure the slump → Difference between cone height and highest point of subsided concrete. 🔹 Types of Slump True Slump ...

🔹 Introduction Brick masonry is one of the oldest and most widely used construction techniques. It involves laying bricks in a systematic manner with mortar to form walls, foundations, partitions, and other structural elements. The strength, durability, and quality of a building highly depend on the workmanship and method of brick masonry. 🔹 Types of Bricks Used First-Class Bricks – Uniform in size, well-burnt, sharp edges, high strength (≥ 10.5 N/mm²). Second-Class Bricks – Slightly irregular, used for internal walls or plastered surfaces. Third-Class Bricks – Poor quality, used for temporary structures. Fly Ash Bricks / AAC Blocks – Lightweight, eco-friendly alternatives. 🔹 Mortar for Brick Masonry Common Mix Proportions : 1:3 (Cement:Sand) → Load-bearing walls. 1:4 or 1:6 → General wall construction. Lime mortar → Traditional works. Mortar should be workable, cohesive, and not too wet. 🔹 Techni...

🔹 Introduction Deshuttering (also called decentring or formwork removal ) is a crucial activity in RCC construction. It refers to the removal of shuttering/formwork after the concrete has gained sufficient strength. Proper Deshuttering ensures structural safety, avoids cracks, and maintains the designed shape and finish. 🔹 Important IS Code Reference According to IS 456:2000 (Clause 11.3.1) – the time for Deshuttering depends on concrete strength, span, type of member, temperature, and curing . 🔹 General Time for Deshuttering (As per IS 456:2000) Vertical Formwork (Columns, Walls, Sides of Beams): 16–24 hours Soffit Formwork (Slabs, Beams): Slabs (props left under) → 3 days Beams (props left under) → 7 days Removal of Props: Slabs (up to 4.5 m span) → 7 days Slabs (over 4.5 m span) → 14 days Beams & Arches (up to 6 m span) → 14 days Beams & Arches (over 6 m span) → 21 days 🔹 Deshuttering Procedure ...

  Columns are key structural elements that transfer loads from slabs and beams to the foundation. For strength, durability, and architectural appearance, column plastering is carried out after proper curing of RCC works. This article explains the technical aspects, step-by-step procedure, and important quality checks of column plastering as per construction practices. 🔹 Purpose of Column Plastering Protection – Provides a cover against weathering, ingress of moisture, and carbonation. Repair – Covers honeycombing, surface voids, and shuttering marks on RCC columns. Alignment – Maintains uniformity of column faces in line with beams and walls. Finish – Ensures smooth, paint-ready surface for interiors and exteriors. 🔹 Technical Specifications (General Practice) Mix Proportion : Cement: Sand = 1:4 to 1:5 (as per IS 1661:1972) Plaster Thickness : 12–15 mm (should not exceed 20 mm in single coat) Sand : Clean, w...