Bricks Of Egypt PC

Many clay products require the addition of other materials to add strength and durability. In the case of bricks in OT Egypt -- river clay is usually composed of very fine particles and so would dry slowly. Adding straw would "open up" the clay, allowing it to dry more readily and so be more promptly and successfully fired. In addition to aiding in drying, the linear nature of straw adds stability to the clay brick in much the same way that rebar or wire mesh reinforce modern day concrete. Bricks made without straw would break and crumble easily. Adobe bricks used around the world are generally only sun dried but grasses, straw and other materials are added to the clay for the same basic reasons.

The ancient brick-making process can still be seen on Egyptian tomb paintings in the Metropolitan Museum of Art (reproduced on page 22 of this pdf)