Lightweight aggregates produced from sand sludge and zeolitic rocks

• Zeolitic rock improves the characteristics of lightweight aggregates.
• Introduction of 20% zeolitic rock reduces the temperature required by 50 °C.
• Lightweight aggregates with the addition of zeolitic rocks have a total porosity of 60–70%.

This paper reports the results of investigations on manufacturing lightweight aggregates from sand sludge with zeolitic rocks added to decrease the foaming temperature. Sand sludge is a waste product from crushing and screening plants for sand and gravel production. Introduction of 20% zeolitic rock into the raw mix composition reduces the temperature required to produce lightweight aggregates by 50 °C and improves their physical–mechanical characteristics. Lightweight aggregates using sand sludge with zeolitic rocks added have porous structures, with a total porosity of 60–70%; this material is recommended for use as lightweight aggregates for concrete and as heat-insulating filling.