---
title: "Surkhi mortar in brief"
subject: "Civil Engineering Materials"
chapter: 6
key: "semester_3/civil_engineering_materials:surkhi-mortar"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/surkhi-mortar
site: BCT Engineering
---

# Surkhi mortar in brief

Civil Engineering Materials · Chapter 6: Mortar

- Asked in: 2080 Bhadra, 1 marks; 2080 Baisakh, 0.5 marks (asked 2 times)
- Video: [CE 209 Functions of sand and surkhi in lime mortar by Sandeep Sharma,SGVGPC,Bharatpur](https://www.youtube.com/watch?v=g9LR7hpz3_k) — SGVGPC Bharatpur
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/surkhi-mortar
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-6

## Question

Describe (define) surkhi mortar.

## Short answer

Surkhi mortar is made by mixing lime with surkhi (finely ground burnt brick) in about 1:2 with water. The surkhi acts as a pozzolana, giving hydraulic properties, making it cheaper and damp-resistant for ordinary buildings, though weaker than cement mortar.

## Answer

**Surkhi mortar** is made by mixing lime (fat lime or hydraulic lime) with **surkhi** (finely ground burnt brick or burnt clay), in a ratio of about 1:2, and water. The surkhi acts as a pozzolana and gives the mortar hydraulic properties. It is used for ordinary buildings, foundations and damp places where cement is costly; it is cheaper and resists dampness, but it is weaker than cement mortar.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Surkhi mortar is made of:
   A. Cement and sand
   B. Mud and straw
   C. Gypsum
   D. Lime and powdered burnt brick in about 1:2
   Answer: D. Surkhi acts as a pozzolana. (Key point: Composition)

2. Compared with cement mortar, surkhi mortar is:
   A. Cheaper but weaker
   B. Stronger
   C. More costly
   D. Not hydraulic
   Answer: A. Used in wet places where cement is costly. (Key point: Property)

3. Surkhi gives the mortar:
   A. Colour only
   B. Hydraulic properties
   C. Fire resistance
   D. Flexibility only
   Answer: B. As pozzolana. (Key point: Role)

## Related in Civil Engineering Materials

- [Define mortar in brief](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Adefine-mortar) — Civil Engineering Materials, chapter 6, asked 4×
- [Gauged mortar in brief](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Agauged-mortar) — Civil Engineering Materials, chapter 6, asked 2×

## Related in other subjects

- [Functions and properties of mortar](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-functions-properties) — Building Technology, chapter 3