Mud walls have been used for buildings since ancient times. Mud wall buildings can be seen all over the world and construction techniques are still in vogue in many parts of the world. Cob wall, adobe, rammed earth, and wattle and daub are some of the common techniques of building mud walls. The use of clay for the construction of the wall has distinct advantages. The clay is easily available locally, low cost, recyclable and environmentally friendly and provides better thermal comfort than other materials. The main drawbacks of mud walls are the greater wall thickness, the loss of strength in saturation and erosion due to the impact of rainfall. These drawbacks can be minimized (or) eliminated using soil stabilization techniques. Stabilized clay blocks are produced through soil stabilization processes. Stabilized clay blocks can be prepared by compacting a wet mixture of soil and cement in a machine. Also known as compressed earth blocks (or) blocks of soil-cement when only cement is used as a binder.
Masonry mortar is a homogeneous mixture comprising fine aggregates, binder material and water. In the current scenario, where the supply of sand does not meet demand, it is essential to find an alternative. Mud mortar was commonly used for low-rise masonry buildings in the past. When the soil used for mortar contains clay, problems such as volume instability due to its high affinity for water. To deny this effect, it is necessary to stabilize the mortar. Cement and lime are used binders individually and in combination. The paper focuses on an experimental study to understand the various characteristics of stabilized clay mortars. The workability and strength of 12 different combinations of stabilized clay mortars have been examined. Flow table tests were performed to quantify the workability of mortars. It was observed that the water requirement of the mortar to reach 100% flow increases with the increase of the clay fraction of the mortar mixture. In the present work, the feasibility of replacing the sand partially or totally with the red soil and the locally available brick powder is studied. The mortar was tested with the alternative fine aggregates, mixed with different combinations of binder materials, ie cement and lime, for 28 days of compressive strength. Mortar with 50% sand and 12% cement replacement has compressive strength in the range of 4.25MPa which is acceptable to IS code specification, the minimum requirement of mortar strength is 3 MPa. Therefore, the use of mortar stabilized in the construction would prove to be sustainable as well as economic.