Chapparu is an innovative practice borne out of adversity to cope with a wide variety of brick sizes to build walls of a given width. It is also the name given to mortar that is applied on the side of a brick on the header course to make the sides appear flat-as-a-plate when single-brick thick walls are built using the English bond. Moreover, it is also a type of joint which holds the bricks together. Such brickwork may be labelled EIS 'chapparu brickwork'.
Output characteristics of such brickwork are studied with respect to variations in brick and joint sizes using a simulation methodology. Simulation trials are undertaken using output rates of macroactivities established using the activity sampling and the synthesis techniques to establish rates and rates for 'three scenarios', viz. fastest and the slowest rates of working including an average rate. Brickwork output under different combinations of study variables are predicted by selecting a 'representative-unit' of brickwork in five randomly chosen walls for which purpose volume of mortar in different joints of the representative-unit and the number of bricks had to predicted using a separately validated model. Micro-activity rates were then used to build up the time taken for each course of brickwork and thereby predict the time taken for building a wall of a specific size. Hourlyoutputs were so calculated repeating the simulation for the 'three scenarios' as necessary. A general specification for increasing hourly output is developed using such analyses which recommends the use of large bed joints and taller bricks, in addition to smaller (or no) vertical joints adopting a flexible approach to lap requirements and joint sizes, including the use of under filled or unfilled vertical joints. Moreover, in order to rrunimise the negative impact of chapparu, it recommends smaller chapparu joints (<10-12mm) as the impact on output is insignificant at such values when current methods of construction are used. Nevertheless, it is noted that increase in output may not necessarily translates to savings in cost.
The simulation methodology developed under this study is a versatile approach for evaluating different scenarios when compared with regression models. It can also be used for evaluating new methods of construction with relative ease.
It is expected that this first time study would clear common understandings surrounding chapparu brickwork thereby exploring new opportunities through a non-standardisation route!
How to Cite:
Abesekera, V., (2010). Output Characteristics of 'Chapparu' Brickwork. Engineer: Journal of the Institution of Engineers, Sri Lanka. 43(4), pp.57–73. DOI: http://doi.org/10.4038/engineer.v43i4.7009