高性能混凝土 (HPC) 為未來營建材料的主流之一，應用在超高層建築及長跨度橋等多項高難度硬體建設，世界先進國家及我國無不積極發展研究。
本研究合成一種新型水溶性之磺酸化酚醛樹脂 (SPF)，作為混凝土的化學摻料，在合成過程中，經由反應條件控制樹脂的分子量、磺酸化程度、鹽類離子等變數，以探討其對水泥漿、流凝土材料性質的影響，並與商用的強塑劑磺酸化三聚氰胺甲醛聚合物（代號M）磺酸化甲醛聚合物（代號F、G）的性能做一比較，另外也探討了 F 強塑劑在水泥表面的吸附行為與添加時間對混凝土工作性的影響。
研究結果顯示：磺酸化較完全的 SPF 對水泥漿黏度下降、混凝土坍流性及抗壓強度的增進有較佳的效果。SPF 的分子量約在3x104左右，有最佳的效果。SPF 若含有少量的鈣離子將增長水泥漿的凝結時間，延緩混凝土的抗壓強度成長，但坍度損失較慢。幾種商業用強塑劑的添加量均在水泥重量的 1﹪～2﹪時有較佳的效果，當添加量不足則效果無法充分發揮，添加量過多 F 強塑劑會泌水或骨材析離，G 強塑劑會嚴重影響水泥的水化致使混凝在護28天後仍不具任何抗壓強度。SPF 與商業用強塑劑比較，唯添加劑量對混凝土性質的影響幅度過大，需再予改進最後，F 強塑劑在水泥粒子上的吸附行為符合 Langmuir 單層等溫吸附模式，摻料的飽和吸附量隨延遲添加時間增加而減少，平衡常數則呈現先減從增的趨勢。推測此與水泥在水化過程中其表面狀態改變，致使摻料的吸附由化學吸附轉變為物理吸附，其轉變時間約為10分鐘（水化潛伏期之前），而由水泥漿流度以及混凝土坍度的結果也顯示適當添加時間應在10～15分鐘左右。

High performance concrete (HPC) is one of the main construction material in the furture. This material has been applied in many areas, such as high-rise buildings and high range bridges. Thus, the research and development of HPC has been carried out worldwide. This study synthesized a new water-soluble sulfonated phenolic resin (SPF) as a chemical admixture for concrete. SPF with different degree of sulphonation, molecular weight, and ion content was made during preparation, and their effects on the material properties of cement paste as well as on those of concrete were investigated. Furthermore, the performance of SPF in concrete was compared with those of superplasticizers. Such as sulphonated naphthalene-formaldehyde condensates (F and G) and sulphonated melamine- formaldehyde condensates (M).
Finally, the adsorption behavior of F superplasticizers. On cement particles was exmined and the effect of addition time of this chemical admixture on the workability of concrete was studied.
The results indicated that SPF with higher degree of sulphonation would reduce the viscosity of cement pastes, improve the sample slump flow properties, and increase the compressive strength of concrete. SPF with weight-average molecular weight of about 3x104 has best performance. The resin containing some Calium ions would prolong the setting time of cement pastes and slow down the strength development of concrete; but the slump loss was improved slightly. The dosage of l~2wt% of all superplasticizers under studied appeared to give the best performance in concrete. For low dosage, the performance of superplasticizers decreased. When dosage greater than 2%, F superplasticizers caused concrete to become bleeding and segregation, and G superplasticizers would impede the cement hydration seriously so that the resulting concrete cured after 28 days exhibited no compressive strength. SPF is as effective as commercial superplasticizers. However, the performance of SPF was sensitive to the dosage which required to be further studied and improved.
Finally, the adsorption behavior of F superplasticizers on cement particles could be described by the Langmuir monolayer isothermal adsorption model. As the addition time of this-chemical admixture increased, the saturated adsorption value decreased, and the equilibrium constant would decrease first, reach a maximum, and then increase slightly afterwords. This trend was speculated to be due to a transition from chemical adsorption to physical adsorption. The transition occurred at about 10 mins, i.e. before the dormant period. This was consistent with the experimental results that the proper addition time for adding superplasticizers in concrete was about 10~15 mins to achieve good workability or slump values.