本實驗所採用的廢觸媒來自石油裂解廠的靜電集塵廢觸媒，主要由SiO2 及Al2O3 所組成且具有部份非結晶相和卜作嵐材料之特性，外觀為乳灰白色粉末、含水量2.8﹪，溶於水中有放熱現象，pH 值為3.85。廢觸媒對水的親和力大，添加至水泥(砂)漿中會使得漿體的流動性減小，因此必須藉由提昇強塑劑劑量才能提高工作度。
在水膠比(W/B)為0.42 時，隨著強塑劑HPC-1000 劑量的增加，水泥漿的流度明顯增加，而且適當量的廢觸媒取代水泥，能維持水泥漿一定的流度。當強塑劑HPC-1000 劑量為3.0﹪、砂/水泥＝2.75 時，隨著水灰比(W/C)的增加，水泥漿的流度也明顯增加，而同條件下，不論水膠比(W/B)0.485 或0.55 時，廢觸媒取代水泥之水泥砂漿的流度比飛灰、爐石、高嶺土好，與矽灰相當，其最佳取代水泥量為15﹪。
As technology continues to develop, a considerable amount of industrial wastes have been produced.In Taiwan, over 6,000 tons of spent catalysts were brought out yearly. If such wastes can be reused in some ways, it may be helpful to protect our environment from being polluted. This study was taken to determine the influence of spent catalysts on the flowability of mortar while the catalysts were used as mineral additives for concrete. Since the catalysts could reduce the flowability of cement pastes because of the affinity between the catalysts and water, it was necessary to have superplasticizers added to improve the fluidity of the mortar.
The spent catalysts used in this study were spent electrostatic precipitator cracking catalysts, called Epcat, which were provided by petroleum refining companies. Comprising mainly silicon oxide and aluminum oxide, the off-white catalyst powder present water content of 2.8%, pH value of 3.85 and exothermic reaction with water.
In this study, it was found that while the ratio of water to binder (W/B) was 0.42, the flowability of the cement pastes increased with the increasing addition of superplasticizers. Besides, the flowability of cement pastes kept steady while a proper amount of Epcat was used to replace cement.When the ratio of sand to cement (W/C) was 2.75, with 3.0% superplasticizers HPC-1000 added,the flowability of the mortars markedly increased while the W/C increased, and the replacement with spent catalysts made the mortars show similar flowability as silica fume but better flowability than fly ash, slag and kaolinite, no matter the W/B value of the cement pastes was 0.485 or 0.55. In fact, the best Epcat replacement for cement was 15%.