Drying shrinkage of cement mortar reinforced with waste office paper fibers

الملخص EN

In this investigation, the influence of using waste office paper fibers (WOPF) on the behavior of drying shrinkage in cement mortar have been presented.

Cement mortar specimens size of (25×25×285) mm and a length change measuring apparatus including a dial gauge capable of measuring the length accurately to ±0.002 mm have been used to study free drying shrinkage of cement mortar according to ASTM C596 – 01 method.

The workability of cement mortar reinforced with WOPF was assessed by using flow table test method.

WOPF was added to the cement mortar in five ratios (0.2%, 0.4%, 0.6%, 0.8%, and 1%) by weight of cement with two categories.

In first one WOPF added after being soaked in water for 24 hours while in the second one WOPF added after being soaked in cooking oil for 48 hours.

The total mixes were 10 in addition to the reference mix (the 11th mix) which is made without WOPF.

The results of the study indicated that the increase in WOPF ratio led to reduce in workability.

In first category, when WOPF ratio increased to 0.4%, the flow percent still within 110±5%, and when WOPF ratio increased to 0.6% and above the flow percent clearly reduced.

While in second category, when WOPF added, the flow percent dropped obviously for all ratios.

Drying shrinkage percent increased when WOPF was added to mixes compared with reference mix for all ratios used in both categories except the fifth ratio (i.e.

WOPF 1%) in which the drying shrinkage percent decreased at age of drying 11, 18, 25 days for first category and at age of 18 and 25 days for second category.

Drying shrinkage percent of mixes has equal ratio of WOPF in the both categories had the same tendency in variation with time.

The loss of weight percent variation for all the mixes is approximately linear.

The loss of weight percent of category I is more than that of category II.