活性粉末混凝土預(yù)制管組合柱抗震性能試驗(yàn)研究

單波 單宇 劉福財(cái) 佟廣權(quán)

摘要：活性粉末混凝土預(yù)制管組合柱（Concretefilled RPC tube，簡稱CFRT）將活性粉末混凝土（Reactive Powder Concrete，簡稱RPC）的力學(xué)性能和箍筋的約束效應(yīng)有效結(jié)合了起來，是一種基于超高性能水泥基套管的新型約束組合柱。對(duì)4個(gè)CFRT柱和1個(gè)箍筋約束混凝土柱開展了恒定軸力下的低周反復(fù)荷載試驗(yàn)，獲取了組合柱的破壞形態(tài)、滯回曲線和鋼筋的應(yīng)變等數(shù)據(jù)，并對(duì)相關(guān)抗震指標(biāo)及試驗(yàn)參數(shù)進(jìn)行了分析。結(jié)果表明：CFRT柱在低周反復(fù)荷載作用下表現(xiàn)出典型的彎曲破壞特征，在RPC管表面出現(xiàn)大量細(xì)而密的裂縫，但沒有明顯的剝落現(xiàn)象;CFRT柱的滯回曲線較飽滿，其抗震性能顯著優(yōu)于普通箍筋約束混凝土柱;在試驗(yàn)條件下，CFRT柱的極限側(cè)移率在0.042～0.075之間，高于中國抗震設(shè)計(jì)規(guī)范關(guān)于罕遇地震下結(jié)構(gòu)柱極限塑性側(cè)移率不低于0.02的要求;從抗震性能來看，在RPC管內(nèi)部填充高強(qiáng)混凝土，對(duì)于CFRT是可以接受的組合方式。

關(guān)鍵詞：活性粉末混凝土;組合柱;反復(fù)荷載;抗震性能

中圖分類號(hào)：TU398 文獻(xiàn)標(biāo)志碼：A 文章編號(hào)：20966717（2020）04009411

收稿日期：20191122

基金項(xiàng)目：國家重點(diǎn)研發(fā)計(jì)劃（2018YFC0705400）;國家自然科學(xué)基金 （51678228）

作者簡介：單波（1976 ），男，博士，副教授，博士生導(dǎo)師，主要從事組合結(jié)構(gòu)和竹木結(jié)構(gòu)研究，Email：supershanb@163.com。

Received：20191122

Foundation items：National Key R & D Program of China （2018YFC0705400）; National Natural Science Foundation of China （51678228）

Author brief：Shan Bo （1976 ）， PhD，associate professor， doctorial supervisor， main research interests： composite structures and modern bamboo structures， Email： supershanb@163.com.

Experimental research on seismic behavior of concretefilled reactive powder concrete tube

Shan Bo1a， 1b， Shan Yu1a， Liu Fucai2， Tong Guangquan1a

（1a. College of Civil Engineering; 1b. Key Laboratory for Green & Advanced Civil Engineering Materials and Application Technology of Hunan Province; Hunan University， Changsha 410082， P.R. China; 2. Guangdong Gaiteqi New Materials Technology Co. Ltd.， Qingyuan 511600， Guangdong， P.R. China）

Abstract： Concrete tube filled reactive powder is a new type of constained composite column based on ultrahigh performance cement casing， with the mechanical properties of reactive powder concrete and the constraint effect of stirrup. In this paper， four ConcreteFilled RPC Tube （CFRT） columns and one ordinary hoopsconfined concrete column were tested under cyclic and constant axial load. The failure mode， hysteresis behavior and strain development of reinforcements were investigated， and the relevant seismic parameters were analyzed. CFRT columns exhibited typical bending failure characteristics. In contrast to conventional reinforced concrete column， the surface of Reactive Powder Concrete（RPC） tube was characterized with well distributed fine cracks， without any RPC cover spalling or crushing.

The hysteresis curve of CFRT cloumn is full， and its seismic performance is significantly better than that of ordinary stirrup confined concrete cloumn. Under the test conditions， the limit plastic drift ratios of CFRT columns vary between 0.042 and 0.075， which largely exceed the specified limit （0.02） according to the rare earthquake requirement in Chinese seismic design code. The results also reveal that RPC tube filled with high strength concrete is an acceptable combination for CFRT columns.

離心法制作RPC管的主要步驟包括：箍筋綁扎、裝模、RPC下料、離心成型、初養(yǎng)護(hù)、脫模、切割和終養(yǎng)護(hù)，基本過程如圖2所示。在制作每根預(yù)制管時(shí)，預(yù)留3個(gè)棱柱體試件（100 mm×100 mm×300 mm）與RPC管同條件養(yǎng)護(hù)。試驗(yàn)前，按照《活性粉末混凝土》（GB/T 31387—2015）[31]進(jìn)行抗壓試驗(yàn)，測得的抗壓強(qiáng)度平均值作為該RPC管的軸心抗壓強(qiáng)度f′rpc，c0。……