respective top and bottom surfaces 52 54 this flat web top edge 68 on both the longitudinal reinforcing web 66 and lateral reinforcing web 67 extends from the intersection of the reinforcement webs 66 67 outwards toward the respective lateral and longitudinal support bars 60 and 62 each flat web top edge 68 is connected to the respective lateral or longitudinal support bar 60 62 by a web slope top edge 70 which extends upwards from the flat web top edge 68 defining the intermediate plane of the support grid 51 to the top edges 61 63 of the respective longitudinal and lateral bars this web slope top edge 70 increases the stability of the reinforcing bars 60 62 by providing support along the entire height of the lateral and longitudinal reinforcing bars the web slope top edge 70 may be a constant slope or also curved as shown in fig1 and 12 but in any event the slope or curve extends between the intermediate plane defined by the flat top edge 68 and the plane defined by the top edges 61 63 of the reinforcing bars 60 and 62 observing fig1 and 14 while the above described lateral and longitudinal side walls 60 62 and lateral and longitudinal reinforcement webs 66 and 67 form a plurality of substantially rectangular or square minor grid sections s the peg bars 58 extend at approximately forty five degree 45 u00b0 angle between adjacent lateral and longitudinal reinforcing bars 62 60 and or lateral and longitudinal reinforcement webs 66 and 67 and alternatively between perpendicularly adjacent webs and bars the peg bars 58 extend at approximately a 45 u00b0 angle relative to each of the respective bars and or.