How to do ground beams

Ground beams are used in situations where foundation walls may not be achievable. Situations where foundations are not achievable is in swampy ares, loose soils, or where the soil bearing capacity is very low. The beams are erected over columns or piers taken into the soil. In home construction, they are used to carry boundary walls or sheds built outside on landscaped soils. They can be erected over drains, sewers or other services in the ground.

                     

                                           Ground beams save on the costs of very deep excavations for foundation and walls. They can carry greater loads in loose soils since they don't rest on the soils. They carry their on weight from column to column. When erecting them, the piers must be already cast in the ground. The size of the beam and reinforcements varies. This depends on the loading to be carried. Reinforcements are high yield twisted bars bent and tied as in the bar bending schedule. 

                                     The ground beam construction procedure commences by clearing the ground. The span between the columns or piers is rammed and compacted. A blinding layer is done with quarry dust. The column or pier reinforcements should be left a foot high to join with the beam. The reinforcements are then tied and bent separately. Once ready, they are carried and laid over the columns and blinding. The reinforcement is laid straight with spacer blocks put at the bottom.

                                                      Once the beam steel is in place, form work is erected to the sides. These must be firmed into the ground and made very tight. This will prevent the escape of the cement slurry when vibrating. After the form work is complete, concrete is prepared and poured into the forms. The process continues while vibrating to ensure the concrete is well bonded with the steel. The top is tamped to be smooth. The forms are removed after seven days while curing.

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